Data Modeling

I. Introduction

The rapid evolution of digital technologies has fundamentally transformed the global financial landscape, reshaping how transactions are conducted, verified, and recorded. Among the emerging innovations driving this transformation, blockchain technology has attracted considerable attention from researchers, policymakers, and industry practitioners due to its potential to enhance transparency, security, efficiency, and trust across financial systems. Originally introduced as the underlying architecture for cryptocurrencies, blockchain has evolved far beyond its initial application and is now being explored across diverse sectors, including banking, accounting, supply chain management, trade finance, and digital payment ecosystems (Treleaven et al., 2017; Chang et al., 2020; Trivedi et al., 2021).

At its core, blockchain is a decentralized and distributed ledger technology that records transactions across a network of participants in a manner that is transparent, immutable, and resistant to unauthorized modification. Unlike conventional centralized databases, blockchain enables multiple stakeholders to access and verify a shared version of transactional records without relying on a single controlling authority. This distributed architecture reduces information asymmetry and strengthens trust among participants, particularly in environments where intermediaries have traditionally played a central role in validating transactions (Kowalski et al., 2021; Chen et al., 2020; Rijanto, 2021). The ability to create a tamper-resistant record of transactions has made blockchain an increasingly attractive solution for addressing long-standing challenges associated with financial transparency, operational inefficiencies, and data integrity (Chang et al., 2020; Lakhani et al., 2020).

The growing adoption of blockchain technology is closely linked to its capacity to streamline business processes and reduce the costs associated with reconciliation, verification, and record management. In traditional financial systems, organizations often maintain separate databases, requiring substantial time and resources to reconcile information across multiple parties. Blockchain addresses this challenge by enabling real-time recording and synchronization of transactions within a shared ledger environment, thereby improving efficiency and reducing the likelihood of errors or fraud (Kowalski et al., 2021; Trivedi et al., 2021; Wang, 2021). Such capabilities are particularly valuable in financial services, where timely access to reliable information is critical for decision-making and risk management (Hassani et al., 2018).

Beyond operational efficiency, blockchain has significant implications for accounting, auditing, and financial reporting. The technology facilitates the creation of transparent and continuously updated records that can be accessed and verified by authorized stakeholders. As a result, auditing processes may become more efficient and reliable because transactional information can be validated directly from the blockchain rather than through extensive manual verification procedures. Importantly, scholars argue that blockchain is unlikely to eliminate the roles of accountants and auditors; instead, it is expected to transform these professions by shifting their focus toward analytical, advisory, and governance functions (Lakhani et al., 2020; Nordgren et al., 2019). Consequently, blockchain should be viewed not merely as an automation tool but as a technological infrastructure capable of reshaping how financial information is generated, shared, and evaluated.

Another notable feature contributing to blockchain’s growing relevance is the emergence of smart contracts. Smart contracts are self-executing digital agreements in which predefined terms and conditions are automatically enforced through computer code. Unlike traditional contractual arrangements that often depend on intermediaries for execution and monitoring, smart contracts facilitate real-time enforcement, reduce transaction costs, and enhance accountability among participating parties (Zhu & Wang, 2019; Li et al., 2020; Katona, 2021). These capabilities have opened new opportunities for decentralized financial services and digital transaction ecosystems, where trust can be established through technology rather than through institutional intermediaries.

Despite its promising advantages, blockchain adoption is not without challenges. Security vulnerabilities, privacy concerns, scalability limitations, and governance issues continue to attract scholarly attention. Researchers have highlighted various threats, including network attacks, smart contract vulnerabilities, and privacy risks that could undermine confidence in blockchain-based systems if not adequately addressed (Chen et al., 2019; Cheng et al., 2020; Dasgupta & Gupta, 2019; Muhammad et al., 2019; Zhang & Xue, 2019; Kadena & Holicza, 2018). Therefore, understanding both the opportunities and risks associated with blockchain implementation remains essential for organizations seeking to integrate the technology into financial infrastructures.

These developments are particularly relevant in the context of Mobile Financial Services (MFS), which have become a cornerstone of financial inclusion in many developing economies. In Bangladesh, MFS platforms have experienced remarkable growth over the past decade, enabling millions of users to access digital financial services through mobile devices. However, challenges related to security, transparency, fraud prevention, transaction verification, and user trust continue to influence the effectiveness of these platforms. Blockchain technology presents a potentially transformative solution by enhancing transaction security, improving traceability, reducing dependence on intermediaries, and fostering greater trust among service providers and users (Bogucharsky et al., 2018; Hofmann et al., 2018; Dong et al., 2022).

Given the expanding role of digital finance in Bangladesh and the increasing importance of secure and transparent financial ecosystems, examining the integration of blockchain technology within MFS platforms has become both timely and necessary. While existing studies have extensively explored blockchain applications in finance, supply chains, and decentralized systems, relatively limited attention has been devoted to understanding its implications within the Bangladeshi MFS sector. Therefore, this study seeks to analyze the impact of blockchain technology on Mobile Financial Services in Bangladesh, with particular emphasis on its potential to enhance security, operational efficiency, transparency, trust, and overall service quality. By exploring these dimensions, the study contributes to the growing body of literature on blockchain-enabled financial innovation and offers insights that may support policymakers, financial institutions, technology providers, and regulators in shaping the future of digital financial services in Bangladesh.

2. Methodology

2.1. Research Design and Rationale

This study followed a qualitative, literature-based design rather than an empirical one — no surveys were fielded, no transaction logs were obtained, and no human participants were involved. That choice was deliberate rather than a fallback. Blockchain adoption within Bangladesh's mobile financial services (MFS) sector is still nascent enough that primary, transaction-level data are scarce, fragmented across institutions, or simply not public, particularly for the bKash–Valyou–Standard Chartered remittance corridor examined later in this paper. Given that constraint, a structured synthesis of existing peer-reviewed and industry literature offered the more defensible route to answering the research question: how, and to what extent, does blockchain technology address the security, privacy, and operational weaknesses already documented in Bangladeshi MFS platforms such as bKash, Upay, Rocket, and Nagad? We treat this as a narrative review with an explicit, reproducible search and selection process, rather than a full systematic review — a distinction we return to in the Limitations section, since the two carry different evidentiary weight and we don't want to overstate what was done here.

2.2. Information Sources

Five databases anchored the search: Google Scholar, IEEE Xplore, the ACM Digital Library, ScienceDirect, and SpringerLink. These five were not chosen arbitrarily; together they cover the disciplinary spread the topic actually demands — IEEE Xplore and ACM for the more technical, systems-security side of blockchain (consensus protocols, smart-contract vulnerabilities), and ScienceDirect, SpringerLink, and Google Scholar for the financial-technology, supply-chain, and policy literature where blockchain's institutional and economic implications are debated. No single database indexes both sides of that conversation well, which is precisely why a multi-database approach was necessary here rather than a convenience choice.

Beyond the five databases, supplementary material was drawn from institutional and news sources where peer-reviewed coverage was thin or simply didn't exist yet — most notably for the 2016 Bangladesh Bank cyber-heist case and the 2020 bKash–Standard Chartered–Valyou remittance launch, both of which are documented mainly in financial press (e.g., reporting referenced in relation to the Financial Times and BBC) and corporate press releases rather than in indexed academic journals. We're upfront that this is a limitation of relying on a country-specific, still-emerging case: academic publication simply hasn't caught up to the event yet, so grey literature filled that gap.

2.3. Search Strategy

Search terms combined three conceptual clusters using Boolean operators, structured to capture (a) the technology itself, (b) its financial-sector applications, and (c) the Bangladesh-specific context:

• Cluster 1 (technology): "blockchain," "distributed ledger technology," "smart contracts," "consensus algorithm," "proof of work," "proof of stake"
• Cluster 2 (application domain): "FinTech," "mobile financial services," "mobile banking," "digital payment," "cross-border remittance," "blockchain security," "blockchain privacy"
• Cluster 3 (geography): "Bangladesh," "bKash," "developing economies," "financial inclusion"

Searches combined terms across clusters (e.g., "blockchain AND mobile financial services AND Bangladesh"; "smart contract AND vulnerability"), and were run iteratively rather than as a single static query — once early reads surfaced more precise vocabulary (for instance, "Lazarus Heist" or "permissioned blockchain"), those terms were folded back into later search rounds. No fixed date range was imposed; given that blockchain's financial-sector literature is still young, restricting by year risked excluding foundational early work without much offsetting benefit. The most recent search pass across all five databases was completed before manuscript drafting began, and citation chaining (manually checking the reference lists of key retrieved articles, e.g., Chang et al., 2020; Muhammad et al., 2019) was used to catch sources the keyword search alone missed.

2.4. Eligibility Criteria

Inclusion was based on relevance to at least one of four thematic pillars described below (Section 2.5), and sources had to be in English and accessible in full text through the author's institutional access or open repositories. We included peer-reviewed journal articles, peer-reviewed conference proceedings, and — for the country-specific case material where peer-reviewed coverage was unavailable — credible financial and technology news outlets and institutional documents (e.g., Bangladesh's ICT Division national blockchain strategy document).

Sources were excluded if they addressed blockchain purely from a cryptocurrency-trading or speculative-investment angle with no bearing on financial-services infrastructure, security, or privacy; if they were not available in full text; or if they duplicated findings already captured by a more comprehensive source on the same topic (in which case the more comprehensive source was retained). We did not apply a formal quality-appraisal instrument such as AMSTAR or the Mixed Methods Appraisal Tool — partly because the heterogeneity of source types (technical surveys, industry reports, news coverage) makes a single appraisal tool a poor fit, and we flag this honestly as a methodological limitation rather than papering over it.

2.5. Thematic Synthesis Framework

Once screened, sources were read in full and organized — manually, by the author, without specialized qualitative-coding software — around four thematic dimensions that emerged from an initial read of the broader literature and were then used to structure both the search and the subsequent synthesis:

1. Conceptual foundations — blockchain's architecture, consensus mechanisms, smart contracts, and the cryptographic primitives underpinning the technology.
2. Security and privacy aspects — established security principles (defense in depth, least privilege, vulnerability management, risk management, patch management) and blockchain-specific privacy characteristics, drawn substantially from Hassani et al. (2018).
3. Application context — documented blockchain use cases in banking (payments, settlement, securities, lending, KYC) and broader digital transactions, alongside a parallel review of real-world attacks and exploits affecting exchanges, wallets, and smart contracts.
4. Country-specific case analysis — the current state of blockchain adoption in Bangladesh, including the 2020 national blockchain strategy and a focused case study of the country's first blockchain-enabled cross-border remittance corridor (bKash–Valyou–Standard Chartered).

This framework functioned less as a rigid coding scheme and more as an organizing scaffold: each retrieved source was read against all four dimensions, and where a single source spoke to more than one (which was common — Chang et al., 2020, for instance, touches both conceptual foundations and application context), its content was distributed accordingly rather than forced into one bucket.

2.6. Data Extraction and Synthesis Procedure

For each included source, the following were extracted manually into a structured reference table: author(s), publication year, title, and database or source of retrieval. This extraction is summarized in Table 1, which lists twelve of the most central sources reviewed (spanning Google Scholar, Wiley Online Library, ACM Digital Library, SpringerLink, IEEE Xplore, and ScienceDirect) as a representative — rather than exhaustive — record of the broader pool consulted; the full reference list at the end of this paper reflects the complete set of sources cited in synthesizing the findings.

Synthesis itself was narrative and descriptive-analytical: findings across sources were compared for points of convergence (for example, multiple independent surveys identifying smart-contract vulnerabilities and wallet-related exploits as recurring attack vectors; Chen et al., 2019; Cheng et al., 2020; Kadena & Holicza, 2018) and for points of tension (for example, the trade-off between blockchain's traceless-transaction capability and its potential misuse for tax evasion, raised in the FinTech literature). Where the same event or figure was reported across more than one source, the most detailed or most

Table 1. Summary of key literature reviewed on blockchain security, privacy, and FinTech applications. Twelve representative sources retrieved through the multi-database search strategy described in Section 2 are listed, spanning the period 2017–2020 and covering blockchain security surveys, privacy frameworks, and adoption barriers relevant to the financial sector. For each source, the table reports the author(s), title, year of publication, and the database through which it was retrieved (Google Scholar, Wiley Online Library, ACM Digital Library, SpringerLink, or IEEE Xplore). This table is intended as a representative cross-section of the broader literature pool consulted, not an exhaustive bibliography; the full set of sources synthesized in this review is listed in the References section.

frequently corroborated account was retained as the primary citation. No statistical meta-analysis was performed or intended, given the qualitative and conceptual nature of the underlying material.

2.7. Reproducibility and Transparency

In the interest of letting other researchers retrace and, if they choose, extend this work, every search term, database, and inclusion decision is reported above rather than summarized vaguely as "a literature review was conducted." We follow the spirit of PRISMA 2020 reporting transparency for evidence synthesis (Page et al., 2021) in how the search and selection process is documented here, while stopping short of claiming formal PRISMA compliance, since this is a narrative rather than a systematic review and no dual-reviewer screening, PROSPERO registration, or formal risk-of-bias assessment was undertaken. Anyone wishing to replicate or update this synthesis would need, at minimum, to rerun the search clusters described in Section 2.3 against the five databases listed in Section 2.2, apply the eligibility criteria in Section 2.4, and organize retrieved material against the four thematic pillars in Section 2.5 — a process that is described here precisely so it can be repeated, not just summarized after the fact.

3. Results

3.1. Overview of the Reviewed Literature

A useful place to start is with what the literature, taken as a whole, actually agrees on — because there is more agreement here than the diversity of sources might suggest. Muhammad et al. (2019) conducted a systematic review of blockchain in FinTech and the role it plays, finding that implementing blockchain in FinTech has allowed banks and non-bank entities to make cross-network transfers and payment services more convenient without involvement of third-party entities, and that by 2030 the annual growth rate would surpass 100%. That is a striking projection, and it's worth sitting with for a moment: it implies not a gradual layering of blockchain onto existing rails, but something closer to a structural shift in how transfers get authorized at all. The authors' enthusiasm rests largely on one mechanism — the peer-to-peer system of keeping the same ledger book ensures no alteration of records, which the authors treat as a primary concern for any financial record-keeping entity.

A related strand of work looks at what a blockchain-based, bank-free mobile payment system would actually look like in practice, and the mechanics are a little more involved than "no middleman." In one such design, a delegation setup allows the bank to act as a delegator named by the payer; the merchant sends a payment request, and once the payment value and merchant identity match, the payer designates the bank as delegate, allowing the bank to issue a blockchain transaction that sells cryptocurrency for fiat currency deposited into the merchant's account, with the blockchain refusing any bank-issued transaction that fails to meet the delegation's conditions. It's an elegant solution to the trust problem — but elegant solutions to trust problems sometimes open other doors. The same traceless quality that protects ordinary users from third-party snooping can also help corrupt individuals evade taxes and facilitate illicit purchases, and that tension — privacy as both a feature and a vulnerability — turns out to be something of a recurring theme rather than a one-off caveat.

Closer to Bangladesh specifically, the picture sharpens. The reviewed sources on financial inclusion converge on three things: blockchain's usefulness, the obstacles standing in its way, and a handful of recommendations for the banking sector. Mechanically, blockchain is a digital ledger of transactions duplicated and distributed across an entire network of computer systems, where each block contains transaction information and any new transaction is recorded in the client's ledger; this decentralized, multi-client database is known as Distributed Ledger Technology (DLT), and compromising it would require a hacker to break every single block in the system — which is, in a sense, the whole security argument in one sentence. Still, the literature doesn't let that strength go unchallenged. A recurring complaint surfaces again and again: blockchain technology is not as user-friendly as most currently used technologies, interfaces for blockchain ledgers remain difficult to adopt, and a scalable solution for handling large numbers of users is necessary before the technology can be used at scale. Even so, on balance, blockchain-based banking is seen as convenient for a developing country like Bangladesh, since it can decrease the rate of corruption in the banking sector. A condensed summary of the literature underpinning this overview appears in [Table 1].

3.2. Blockchain Architecture and Working Mechanism

To make sense of where blockchain helps and where it struggles, it's worth pausing on what the technology actually is — not as an abstraction, but as a working system. Blockchain technology is an amalgamation of cryptography, algorithms, economic models, and mathematics, combining peer-to-peer networking and distributed consensus algorithms to solve the synchronization problems inherent in traditional distributed databases. [Figure 1] lays out this basic architecture. The defining feature isn't really the cryptography itself, interestingly enough, but the absence of ownership: blockchain does not belong to any person or organization, and its design provides a system monitored by all nodes in the network to ensure that transactions and activities are valid, which suggests the lowest possible percentage chance of the system being hacked.

That resilience, though, depends on something easy to overlook — redundancy at scale. Data in the blockchain are stored permanently across all nodes constituting the network, and each node must hold the updated current copy of the blockchain to ensure consistency, with nodes performing activities such as mining, making transactions, and validating other nodes' transactions (Mohanta et al., 2019). [Figure 2] breaks down the eight elements considered central to this architecture.

History and Working Procedure

Blockchain's lineage matters for understanding today's design choices, and [Figure 3] traces that history. The public–private distinction turns out to map fairly cleanly onto two governance philosophies: Bitcoin and Ethereum are public, permissionless blockchains open to anyone, whereas the various Hyperledger networks are private, permissioned blockchains requiring participant verification before joining. As for how a transaction actually moves through the system — illustrated in [Figure 4] — the process unfolds in a fairly linear sequence: a node broadcasts a transaction; another node verifies its authenticity and stores it in a block; all nodes validate the transaction by executing either the proof-of-work or proof-of-stake algorithm on the block awaiting validation; and finally, the consensus algorithm commits the validated data to a block added to the chain, with all nodes accepting that block and extending the chain accordingly. Simple to describe, evidently — though, as later sections show, considerably harder to secure in practice.

3.3. Security and Privacy Aspects

[Figure 5] separates the blockchain properties reviewed here into two camps: security and privacy. They're related, certainly, but they answer different questions, and it's worth keeping that distinction sharp.

Security of Blockchains

On the security side, the working definition adopted here treats it as the protection of transaction information and data in a block against internal, peripheral, malevolent, and unintentional threats, typically through detection, prevention, and appropriate response using security policies, tools, and IT services. Five principles recur throughout the reviewed sources, and they're fairly standard information-security doctrine applied to a less standard substrate: defense in penetration, which follows the principle that protecting data in multiple layers is more efficient than relying on a single security layer; minimum privilege, which reduces data access to the lowest level possible to reinforce security; vulnerability management, involving identification, authentication, modification, and patching; risk management, involving identification, assessment, and control of environmental risks; and patch management, which addresses flawed code, applications, operating systems, and firmware through acquiring, testing, and installing patches. None of these principles is unique to blockchain, to be fair — but their application here carries higher stakes, given the immutability that makes correcting a security failure after the fact so much harder than on a conventional database.

Privacy of Blockchains

Privacy asks a narrower, more pointed question: can transactions be performed without leaking identification information, making it extremely difficult for other users to copy or use someone else's crypto profile? Drawing on Hassani et al. (2018), five characteristics recur as particularly significant. First, blockchain offers flexibility to store all forms of data, though privacy rules applicable to personal data become more stringent for sensitive and organizational data (Hassani et al., 2018). Second, on storage distribution, nodes storing complete copies of the blockchain are called full nodes, and an application's compatibility with data minimization determines the level of transparency and verifiability available for that application (Hassani et al., 2018). Third — and this one tends to surprise people who assume blockchain records are simply unfixable forever — the append-only feature does not, in certain cases, curtail users' right to correction when data

Figure 1. Basic architecture of a blockchain network. Schematic representation of a distributed ledger shared across participating nodes, illustrating the absence of a single controlling authority. Each node maintains an identical, continuously updated copy of the ledger, and network-wide validation of transactions and activities is distributed across all participants rather than centralized in any one entity — the structural property underlying blockchain's resistance to unilateral tampering.

Figure 2. Core elements of blockchain technology. Diagrammatic overview of the eight components considered foundational to blockchain systems, as discussed in Section 3.2, including the distributed ledger, consensus mechanism, cryptographic hashing, and peer-to-peer network layer that together enable decentralized transaction validation and record-keeping.

Figure 3. Historical timeline of blockchain development. Chronological summary of blockchain's evolution, from its original conceptualization as the architecture underlying Bitcoin through to the emergence of public, permissionless networks (e.g., Bitcoin, Ethereum) and private, permissioned networks (e.g., Hyperledger), illustrating the divergence between open-participation and verified-participation blockchain models discussed

is recorded incorrectly, though special attention is needed when assigning rights to data subjects (Hassani et al., 2018). Fourth, on the private-versus-public distinction, restricted data on a block can be encrypted for conditional access by authorized users at an advanced level, since every node maintains a copy of the entire blockchain (Hassani et al., 2018). And fifth, regarding permission structures, non-permissioned blockchain applications in principle allow all users to add data, whereas permitting the restoration of trusted mediators influences how control over the network is distributed (Hassani et al., 2018).

3.4. Why Blockchain Is Needed in Banking

Here the literature takes on a slightly more pointed tone — less descriptive, more critical of the status quo. Banking institutions worldwide have moved toward digitalization-driven models such as mobile banking, but blockchain adoption within banking has been comparatively sidelined; this hesitation contrasts with the interest blockchain is attracting elsewhere, reflected in the technology's projected growth from $4.9 billion in 2021 to over $67.4 billion by 2026 ([Figure 6]). That is more than a tenfold increase in five years — a pace that makes the banking sector's caution look, frankly, a little out of step with where capital and attention are flowing. The industry advances at a constant speed due to steady demand, yet remains slow to innovate; banks still require considerable paperwork, face security vulnerabilities, and run multiple time-consuming and expensive processes. Five specific applications illustrate where blockchain might close that gap.

Payment transfer. Trillions of dollars are presently made and wasted due to added fees and slow payments respectively — for example, a person sending money from San Francisco to London faces a $25 flat fee charged by both sending and receiving banks. By contrast, cryptocurrencies like Ether and Bitcoin, built on public blockchains, let anyone send and receive money without transaction fees and in real time, since decentralized-network payments require no separate verification step, making transfers faster and cheaper.

Settlement and clearance. An average bank transfer takes up to three days to settle — problematic for consumers and logistically difficult for banks alike, given that a simple transfer today bypasses a complex chain of intermediaries from bank to custodial service before reaching the recipient. Blockchain's transparent, public decentralized ledger allows transactions to settle without relying on custodial services, which is one of the key ways blockchain speeds up and simplifies banking transactions.

Securities. Buying or selling debt, stocks, or commodities requires banks to track ownership by connecting with multiple exchanges, brokers, clearing houses, and custodian banks, and this web of intermediaries, combined with an outdated paper ownership system, makes the process slow and prone to inaccuracy and fraud. Blockchain instead builds a decentralized database of digital, unique assets, transferring them through tokens representing assets "off-chain" — an approach whose benefit lies chiefly in cutting out middlemen and lowering exchange fees.

Loans and credit. Banks typically underwrite loans through a credit reporting system, and blockchain in consumer banking opens the door to peer-to-peer lending — one of the more investment-friendly corners of FinTech. The conventional alternative isn't necessarily fairer: banks evaluate non-payment risk by examining credit score, ownership status, and debt-to-income ratio drawn from a centralized reporting system that can work against customers. A decentralized registry of payment history, by comparison, makes it easier for consumers to apply for loans under an alternate lending system that is comparatively efficient, cheap, and secure.

Customer KYC. Verification delays are not a minor inconvenience here. Banks can take up to three months to complete KYC procedures — photo verification, address proof checks, biometric verification — and the process is costly as well as slow. Storing customer information on a shared ledger changes that math considerably: blockchain-based KYC storage gives banks shared access to verification data, an arrangement associated with personnel cost reductions of roughly 10%, equating to $160 million annually. That single figure does more to justify blockchain's banking case, arguably, than most of the more conceptual arguments combined.

3.5. Blockchain in Digital Transactions

Stepping back from banking specifically, financial service providers find blockchain useful for enhancing authenticity, security, and risk management, with institutions increasingly adopting it in trade and finance to build smart contracts between participants, improve efficiency and transparency, and open newer revenue opportunities ([Figure 7]). Blockchain's recording capabilities make

Figure 4. Working procedure of blockchain transaction validation. Sequential flow diagram depicting the lifecycle of a blockchain transaction: initiation and broadcast by the originating node, verification and provisional storage by receiving nodes, network-wide validation via proof-of-work or proof-of-stake consensus protocols, and final commitment of the validated block to the chain.

Figure 5. Security and privacy dimensions of blockchain systems. Conceptual framework distinguishing the security properties of blockchain (defense in depth, least privilege, vulnerability management, risk management, and patch management) from its privacy-preserving characteristics (data sorting, storage distribution, append-only recording, and permissioned versus non-permissioned access).

Figure 6. Projected global market size of blockchain technology, 2021–2026. Bar chart illustrating the projected growth of the global blockchain technology market from an estimated $4.9 billion in 2021 to over $67.4 billion by 2026, reflecting a more than tenfold increase over a five-year period. Source of underlying market projection should be cited explicitly in the figure caption and added to the reference list (e.g., the original market research report from which this estimate was drawn); the manuscript as currently written does not attribute this statistic to a specific source, which a high-impact journal reviewer is likely to query.

Figure 7. Role of blockchain in digital transaction processing. Schematic illustrating how blockchain technology is applied within trade and finance systems to support smart contract execution between participants, streamline clearing and settlement processes, and enable blockchain-based identity verification.

existing clearing and settlement processes largely redundant, and banks and other financial entities are adopting blockchain-enabled IDs to identify people.

Consensus Algorithms

Anonymity is usually framed as a benefit of blockchain, but it raises an obvious question that the literature doesn't shy away from: how can anonymous users be trusted to act honestly when adding transactions to a ledger? The answer lies in validating every transaction as legitimate — not malicious, not a case of double-spending — before placing it into a block, with the agreement to add that block reached through consensus algorithms, which function as the heart of all blockchain transactions. PoW, PoS, DPoS, and PBFT are the most common consensus algorithms, with DAG standing apart as the most structurally different, while PoET — developed by Intel Corporation — underpins Hyperledger Sawtooth specifically.

Smart Contracts

Beyond providing a distributed, unchangeable record of events, blockchain allows objective computer code to define exactly how a process should be managed and what steps follow a given event; the smart contract proposed within Ethereum was intended, in part, to overcome Bitcoin's limitations, and is sometimes referred to as chain code.

Cryptography for Blockchain

Blockchain creates a layer of trust between untrusted parties to enable secure, trusted records and transactions; absent that layer, a third-party intermediary would be necessary, but blockchain instead uses cryptography and collaboration to build that trust, eliminating the need for a centralized institution as intermediary (Muhammad et al., 2019). Three cryptographic building blocks recur most often: public key cryptography, used for digital signatures and encryption; zero-knowledge proofs, which demonstrate knowledge of a secret without revealing it; and hash functions — one-way, pseudo-random mathematical functions, with Merkle trees adopting them to form part of the block header. [Figure 8] illustrates how digital signatures and hashing function together in a blockchain transaction.

Cryptocurrencies and Supply Chains

Two applications stand out as the most thoroughly documented. On the currency side, cryptocurrency is a digital medium of exchange operating through a computer network independent of any central authority such as a government or bank, with Bitcoin — announced in 2008 and launched in 2009 — as the first such currency, capped at a maximum of 21 million BTC ([Figure 9]). On the supply-chain side, the appeal rests on visibility rather than currency: blockchain's distributed ledgers create a permanent, shared transaction record, visible to authorized participants, traceable, immutable, and irrevocable — properties that have driven growing blockchain use for supply-chain data sharing, exemplified by IBM's permissioned blockchain-based supply-chain solutions with a logistics focus (Treleaven et al., 2017), and by VeChain's cold-chain logistics solution, which tracks logistic information for transparent, regulated, secure, and reliable data sharing (Chang et al., 2020).

Real Attacks and Bugs on Blockchain Systems

It would be a disservice to the technology's record, though, to stop at what it enables without confronting where it has actually failed — and the literature is reasonably candid on this point. Because users rely on exchange platforms to transact and keep private keys in digital wallets, both exchanges and wallets count as parts of the blockchain system, and several documented incidents illustrate the resulting exposure.

The earliest and arguably most consequential bug struck at the protocol's core. Occurring in August 2010, the CVE-2010-5139 vulnerability was the most famous software bug in the Bitcoin network, caused by an integer overflow in its protocol; an invalid transaction of 0.5 BTC was replaced with 184 trillion BTC and added to a normal block, taking more than eight hours to resolve (Chen et al., 2019). Exchange platforms have fared little better in more recent years: in July 2020, hackers breached Cashaa, a UK-based cryptocurrency exchange, stealing more than 336 BTC, and in August 2020, attackers struck the European trading platform 2gether's servers, stealing 1.39 million USD (Dasgupta & Gupta, 2019). Wallets, too, have proven a recurring weak point — on October 23 and 26, 2013, an Australian Bitcoin bank was hacked, and all 4,100 BTC held by the wallet service on a US server were stolen (Zhang & Xue, 2019); a multi-signature vulnerability in the Parity Wallet later allowed a hacker to steal 30 million USD from at least three Ethereum accounts by compromising their addresses on July 19, 2017 (Cheng et al., 2020); and an undiscovered initialization bug in a subsequently deployed version of the Parity Wallet library

Figure 8. Digital signatures and hash functions in blockchain transactions. Diagram illustrating the cryptographic workflow underlying transaction verification, including the generation of a digital signature using public key cryptography and the use of one-way hash functions — incorporated into Merkle tree structures — to ensure transaction integrity and authentication.

Figure 9. Bitcoin logo, the first cryptocurrency built on blockchain technology. Visual symbol of Bitcoin, the original cryptocurrency, announced in 2008 and launched in 2009, with a hard-capped maximum supply of 21 million BTC, included here to anchor the discussion of cryptocurrency as blockchain's earliest and most widely recognized financial application.

contract caused a further incident on November 6, 2017, freezing funds in affected multi-signature wallets (Kadena & Holicza, 2018) — three separate failures within roughly four years, all tracing back to wallet infrastructure rather than the underlying ledger itself. Smart contracts complete the pattern: in January 2018, a hacker exploited an integer overflow bug in smart contracts built on the Proof of Weak Hands (PoWH) coin, stealing 888 ETH, and in October 2018, an attacker executed a reentrancy attack against Spankchain's smart contracts, draining 165.38 ETH. Taken together, these cases suggest the vulnerability rarely sits in the consensus mechanism itself, but rather in the software layered on top of it — a distinction that matters quite a bit for how Bangladesh's own adoption efforts, discussed next, ought to be approached.

3.6. Blockchain Adoption in Bangladesh

Why Bangladeshis Are Adopting Blockchain

If there's a single event that explains the urgency behind Bangladesh's interest in blockchain, it's probably this one. In 2016, North Korean hackers stole $81 million from Bangladesh Bank in what is known as "the Lazarus Heist," the largest cyber heist in the world to date. What makes the episode unsettling isn't merely the sum involved, but where it happened: the money was taken from Bangladesh Bank's account at the New York Federal Reserve, and the hackers managed to access SWIFT — widely considered the most secure method for transferring large sums between banks — even though SWIFT itself has periodically drawn criticism for inefficiency, with the Financial Times noting in 2018 that transfers remain time-consuming, costly, and lacking in transparency. The reaction from outside Bangladesh was telling. As US Congresswoman Carolyn Maloney put it to the BBC, a breach of that scale could fatally undermine confidence in the SWIFT system itself — and Istiaque Ahmed, a blockchain developer and research scientist at the Blockchain Economy Research Center at the Gwangju Institute of Science and Technology in South Korea, has voiced the same concern, suggesting that blockchain adoption could plausibly have prevented frauds of this kind.

Current Scenario in Bangladesh

Adoption so far has been concentrated, rather than widespread. A handful of financial institutions — Standard Chartered Bank, Prime Bank, HSBC Bank, and bKash — have already begun adopting blockchain technology, alongside agro-tech startups such as Krishi Swapno operating pilot projects; Bangladesh-based banks have, in the past two years, executed a number of letters-of-credit transactions through blockchain, and Krishi Swapno, describing itself as a blockchain-based agricultural technology platform, has reportedly implemented blockchain within its supply chain on a pilot basis. Policy has begun to catch up with practice, if cautiously: in March 2020, the ICT Division released Bangladesh's first national blockchain strategy, outlining a three-phase plan aimed ultimately at establishing a comprehensive regulatory sandbox and a National Blockchain Platform — a cloud-based, permissioned blockchain hosted under the relevant government agency, intended to let local companies build blockchain-based services. For now, though, only a few large-scale companies possess the resources needed to adopt blockchain, and successful execution of the National Blockchain Strategy would be required before all companies could meaningfully harness permissioned blockchain.

First Blockchain-Based Instant Transfers from Malaysia

The clearest real-world demonstration of these ideas converging into an actual product arrived in September 2020. On September 9, 2020, Standard Chartered Bank, mobile financial service provider bKash, and Malaysia's digital remittance provider Valyou launched the first blockchain-based remittance service in Bangladesh, powered by blockchain technology from Ant Group. The corridor matters more than it might first appear, given how central remittances are to the national economy: wage-earner remittances from expatriate Bangladeshis represent one of the key pillars of the Bangladesh economy and a major contributor to its foreign currency reserves, and Malaysia is an important part of that remittance ecosystem, with Bangladeshi migrants there who hold bKash wallets able to send wage remittances via Valyou to beneficiaries back home.

Institutionally, Standard Chartered Bank serves as the fund settlement bank and regulatory approval holder for the service, bringing together Standard Chartered, Ant Group, bKash, and Valyou to serve the Bangladeshi diaspora in Malaysia; Ant Group's blockchain technology streamlines the remittance process, radically improving delivery speed while also strengthening information security and transparency, and recipients can cash out at roughly 240,000 nearby agent points nationwide while also accessing bKash's wider service range. The executives involved framed the service in similar terms, each emphasizing a slightly different angle — speed, convenience, cost — but converging on the same underlying claim. Standard Chartered's Bangladesh unit CEO, Naser Ezaz Bijoy, described the solution as making the remittance experience simpler and faster through round-the-clock availability; bKash's CEO, Kamal Quadir, noted that the integration brings considerable convenience to both recipients and senders while contributing further to foreign remittance earnings; and Valyou's CEO, Prasanna Rao, explained that Valyou customers in Malaysia can cash in through online banking, ATMs, and a network of more than 1,300 merchants, with the blockchain integration saving cost and time without compromising the safety and security of remittance transactions flowing from Valyou to bKash.

3.7. Synthesis: What This Means for MFS in Bangladesh

Pulling these threads together, a fairly consistent picture emerges — though not, it should be said, an uncomplicated one. Blockchain technology appears to offer substantial potential to address some of the most persistent weaknesses already documented in Bangladeshi MFS platforms: high service charges, limited transaction privacy, susceptibility to scams involving phone numbers and transaction histories, and vulnerability to large-scale cyber heists of the kind that struck Bangladesh Bank. By decentralizing record-keeping and reducing reliance on intermediaries, blockchain-based MFS could plausibly lower transaction fees, speed up settlement, and provide a tamper-resistant audit trail that strengthens user trust.

Mapping the security and privacy framework from onto these MFS-specific concerns turns out to be a fairly natural fit, rather than a forced one. The security principles reviewed — defense in depth, least privilege, vulnerability management, risk management, and patch management — together with blockchain's privacy-preserving characteristics, map directly onto the concerns most frequently raised about MFS in Bangladesh, including unauthorized access to transaction records and impersonation-based fraud. The bKash–Valyou–Standard Chartered remittance case demonstrates that these benefits are not merely theoretical; they are already being realized in practice, through faster, more transparent, and more secure cross-border transfers.

That said, optimism here needs tempering, and the literature itself is reasonably insistent on this point. Important limitations remain before blockchain can be adopted at scale within Bangladeshi MFS: the technical complexity and poor usability of blockchain interfaces for the general public, the scalability demands of a system that would need to support millions of users, and the documented history of attacks and bugs affecting exchanges, wallets, and smart contracts reviewed in [Section 3.5]. Bangladesh's National Blockchain Strategy, with its proposed permissioned National Blockchain Platform, offers a promising regulatory pathway — but one whose success will hinge on building the technical capacity and infrastructure needed for adoption to spread meaningfully beyond a handful of large institutions

4. Discussion

4.1. Interpreting the Central Finding

Stepping back from the individual findings reported above, what emerges — cautiously, and not without some loose ends — is a reasonably coherent argument: the security and privacy weaknesses most commonly attributed to Bangladeshi MFS platforms are not incidental quirks of bKash, Upay, Rocket, or Nagad specifically, but structural consequences of the centralized architecture all four platforms share. That distinction matters more than it might first seem. If the problem were merely poor implementation by individual providers, the fix would presumably involve better internal controls. But if the problem is architectural — and the literature reviewed here leans toward that reading — then blockchain's appeal lies less in being a better version of the same thing, and more in being a structurally different thing altogether.

The conceptual material reviewed in [Section 3.2] supports this reading reasonably well. Blockchain's defining property, after all, is not really its cryptography in isolation, but the fact that no single actor owns or controls the ledger; validation is distributed across the network, which is precisely the feature that current MFS architectures lack. Mapped onto Bangladesh's documented MFS pain points — privacy invasion of intermediary merchants, scams exploiting known mobile numbers paired with visible transaction histories, and exposure to large-scale institutional breaches such as the one suffered by Bangladesh Bank — that structural difference begins to look less like an abstract technical advantage and more like a fairly direct answer to a fairly specific set of problems.

4.2. Security and Privacy Principles, Reconsidered Against Local Risk

It would be easy to treat the security and privacy framework summarized in [Section 3.3] as a generic checklist imported wholesale from the broader information-security literature — and to be fair, much of it is exactly that. Defense in depth, least privilege, vulnerability management, risk management, and patch management are not blockchain-specific concepts; they predate blockchain by decades. What's worth dwelling on, though, is how naturally these principles map onto the specific failure modes Bangladesh has already experienced. Defense in depth, for instance, speaks directly to the Bangladesh Bank episode, where a single compromised credential chain at one institution cascaded into an $81 million loss; a system requiring validation across multiple independent nodes, rather than trust in one centralized gateway, would have made that particular failure considerably harder to engineer.

Privacy, though, is where the argument gets more interesting — and admittedly a little more uncertain. The privacy characteristics drawn from Hassani et al. (2018) and discussed in [Section 3.3] describe a system that can, in principle, keep transaction details visible to authorized participants while shielding personal identifiers from casual exposure. That sounds like a near-perfect fit for the scam pattern documented in Bangladesh, where fraudsters exploit visible mobile numbers paired with inferred transaction history. But "in principle" is doing a fair amount of work in that sentence. None of the reviewed sources offer empirical evidence, specific to Bangladesh's MFS context, that a blockchain-based redesign would actually eliminate this scam vector in practice rather than simply relocating it — a gap this paper does not resolve and, frankly, could not resolve through literature synthesis alone.

4.3. The Remittance Case as Evidence, Not Proof

The bKash–Valyou–Standard Chartered case described in [Section 3.6] deserves particular attention here, because it shifts the discussion from what blockchain could theoretically do to what it has, in one specific instance, actually done. Launched in September 2020, the corridor connecting Malaysia-based remitters to Bangladeshi recipients through Ant Group's blockchain infrastructure is, as far as the reviewed literature indicates, the country's first operational demonstration of blockchain-enabled MFS at meaningful scale — and the claims made by the executives involved, while naturally promotional in tone, are at least directionally consistent with the theoretical benefits discussed earlier: faster settlement, stronger information security, and reduced reliance on the kind of multi-intermediary chain that makes conventional remittances slow and costly.

Even so — and this caveat seems worth stating plainly rather than burying it — a single corridor, run by three well-resourced institutional partners with regulatory backing from Standard Chartered, is a long way from evidence that blockchain-based MFS would work as smoothly for Bangladesh's smaller-scale, higher-volume domestic platforms. The remittance case benefited from concentrated institutional capacity that bKash, Upay, Rocket, or Nagad would each need to replicate independently, or coordinate around collectively, before similar benefits could plausibly extend to everyday domestic transfers. This paper treats the case as suggestive evidence of feasibility, not as proof of scalability, and that distinction seems important enough to flag rather than gloss over.

4.4. Weighing Benefits Against Documented Risks

None of this is to suggest blockchain arrives risk-free, and the literature reviewed in [Section 3.5] is fairly unambiguous on that point. The pattern of real-world attacks and bugs documented there — the CVE-2010-5139 integer overflow in Bitcoin's core protocol (Chen et al., 2019), the Cashaa and 2gether exchange breaches (Dasgupta & Gupta, 2019), the Australian wallet theft (Zhang & Xue, 2019), the Parity Wallet vulnerabilities (Cheng et al., 2020; Kadena & Holicza, 2018), and the PoWH and Spankchain smart-contract exploits — is not a list of edge cases. It is, taken together, a fairly consistent signal about where blockchain systems actually break, which turns out to be informative in its own right: rarely at the level of the core consensus mechanism, and far more often in the software layered on top of it — wallets, exchanges, and smart contracts written by fallible developers rather than the underlying ledger itself.

That distinction carries a fairly direct implication for how Bangladesh's MFS sector ought to approach adoption, if it chooses to. The risk calculus is not "blockchain versus no blockchain," but rather a question of where engineering rigor gets applied. A poorly audited smart contract layered on top of an otherwise sound blockchain is not meaningfully safer than a poorly secured conventional database — arguably, given the added complexity, it could be worse. This suggests that any Bangladeshi blockchain-MFS initiative would need to invest as heavily in smart-contract auditing and wallet security as in the underlying ledger architecture itself, a point the reviewed literature does not always state explicitly but seems to imply fairly strongly once the attack history in [Section 3.5] is read end to end.

4.5. Usability and Scale: The Two Persistent Counterarguments

Two limitations recur often enough across the sources reviewed that they deserve treatment as genuine counterarguments, rather than minor caveats tacked onto an otherwise optimistic conclusion. The first is usability. Multiple sources converge on the observation that blockchain interfaces remain difficult for ordinary users to adopt, and this is not a trivial concern for a country where MFS platforms succeed in large part because of their simplicity — bKash and its counterparts work for tens of millions of users precisely because the interface asks almost nothing of them. A blockchain-based MFS redesign that reintroduces complexity in exchange for security would risk undermining the very accessibility that made MFS transformative in Bangladesh in the first place. Whether that trade-off is worth making is ultimately an empirical and design question this review cannot settle.

The second is scale. A system built to serve a handful of institutional partners, as in the remittance case discussed above, faces a fundamentally different engineering challenge than one built to serve the tens of millions of active MFS users already on bKash, Upay, Rocket, and Nagad combined. The literature acknowledges this gap candidly rather than minimizing it, and Bangladesh's own policy response — the National Blockchain Strategy released by the ICT Division in March 2020, discussed in [Section 3.6] — seems to reflect awareness of exactly this tension, given its phased, sandbox-first approach rather than an attempt at immediate national rollout.

4.6. Positioning This Study Within the Broader Literature

It is worth situating this paper's contribution against the wider body of work it draws on. Much of the existing scholarship on blockchain in finance — Treleaven et al. (2017), Chang et al. (2020), Trivedi et al. (2021), among others — addresses the technology's implications for finance broadly, or for specific applications such as trade finance (Bogucharsky et al., 2018; Kowalski et al., 2021), supply chain finance (Chen et al., 2020; Lakhani et al., 2020; Rijanto, 2021; Wang, 2021), or accounting and auditing (Lakhani et al., 2020; Nordgren et al., 2019), generally without sustained attention to any single developing-economy MFS ecosystem. What this paper adds, modestly, is a synthesis that brings the general security and privacy literature (Chen et al., 2019; Cheng et al., 2020; Dasgupta & Gupta, 2019; Kadena & Holicza, 2018; Zhang & Xue, 2019) into direct contact with a specific national context where MFS adoption is unusually deep and unusually visible. Whether that synthesis generalizes to other developing economies with comparably mobile-first financial ecosystems is a question this paper does not attempt to answer, but one that seems worth raising for future comparative work.

4.7. Limitations of This Review

A few limitations are worth stating directly rather than leaving implicit. First, this study is a literature-based synthesis rather than an empirical investigation; no primary transaction data, user surveys, or institutional interviews were collected, which means the conclusions drawn here describe what the literature suggests is plausible, not what has been independently verified through original data collection. Second, much of the country-specific material — particularly around the Bangladesh Bank heist and the bKash–Valyou–Standard Chartered remittance launch — relies on financial press coverage and corporate statements rather than peer-reviewed sources, simply because peer-reviewed treatment of these specific events does not yet exist in meaningful depth; this is a function of how recent and how narrowly scoped these events are, rather than a methodological shortcut taken lightly. Third, the reviewed attack literature, while useful for establishing a pattern, draws disproportionately from global cryptocurrency exchanges and wallets rather than from MFS-specific blockchain deployments, of which there are still too few in operation to support a literature base of comparable depth. Readers should weigh the conclusions accordingly.

4.8. Implications and Directions for Future Work

Taken together, the discussion above points toward a fairly specific research agenda rather than a vague call for "more study." Future work would benefit from empirical evaluation of blockchain-based MFS pilots at a scale closer to bKash's actual user base, rather than relying on extrapolation from a single institutional remittance corridor; from usability research that tests whether blockchain-based interfaces can be simplified enough for Bangladesh's broad and not uniformly tech-literate user base without compromising the security properties that motivate adoption in the first place; and from closer engagement with the practical mechanics of Bangladesh's National Blockchain Strategy as its phases unfold, since the sandbox model will generate exactly the kind of implementation data this review found lacking. Smart contract auditing standards, specific to financial applications, also seem like an underexplored area worth closer attention, given how much of the documented attack history in traces back to contract-level rather than ledger-level failures.

5. Conclusion

Blockchain is one of the most recently established technologies, highlighting the concepts and advancements of the Internet of Things (IoT) and artificial intelligence revolutions. Cryptocurrencies like Bitcoin and Ethereum are basically developed using blockchain technology. Blockchain technology enables online value transfers without the use of a middleman such as a bank or credit card firm. Blockchains, or distributed ledgers, are a new innovation that has emerged in the recent decade. It is a known fact that the current generation of Bangladesh is growing up with smart devices and is adopting technology very quickly. For this reason, Mobile Financial Services are growing very fast, having already foreseen their future success. The current MFS allows users to access mobile banking, utility or merchant payments, e-commerce payments, and many more services. However, the current MFS system has some limitations, such as higher service charges, safety issues, limited features, and hacking issues. There is a lot of space for further study, and with further research into the uses of blockchain in the financial industry, smart contracts can be implemented and privacy can be substantially increased.

References