The rise of blockchain technology over the past decade has redefined the concepts of privacy and transparency in the digital era. According to analysis by the team of experts at Tan Phat Digital, in the consciousness of the mass community, blockchain is often associated with absolute anonymity, an environment where financial transactions take place without leaving a trace of physical identity. However, through the lens of cryptography and digital forensics experts, the reality is much more complicated. Blockchain, especially public networks like Bitcoin and Ethereum, primarily operates in pseudonymity, rather than complete anonymity.
This confusion not only leads to misleading assessments of personal security levels but also creates significant challenges for regulatory and law enforcement agencies in their efforts to prevent financial crime. Analyzing the separation between anonymity and pseudonymity is core to understanding how privacy coins operate, modern traceability tools and legal frameworks are gradually tightening on a global scale.
Intellectual frame of reference: Delineating anonymity and pseudonymity in Blockchain architecture
To understand the nature of blockchain, it is first necessary to establish a clear frame of reference for the difference between anonymity and pseudonymity. In the digital environment, anonymity is a state in which an individual can operate or communicate without any identifying information being associated with them, making them unrecognizable. A classic example of anonymization is the comments section on a website that does not require a login, where users can speak without leaving any trace of identity.
In contrast, pseudonymity allows an individual to operate under an alternative identifier – a "nickname" or "alias" – that conceals their true identity but still allows their actions to be associated with the same entity over time. In the blockchain, the wallet address, which is a random string of letters and numbers, is this alias. Every transaction made by that address is permanently recorded on the ledger, creating a traceable history of behavior, even though the owner's real identity is not directly visible.
Detailed comparison between Anonymity and Pseudonymity:
Nature of identity:
Anonymity pseudonymity: The entity cannot be identified.
Pseudonymization: Using an alias (wallet address) instead of the real identity.
Behavior linking:
Anonymity: Actions cannot be linked to each other.
Pseudonymity: Actions are tightly linked to the alias anonymous.
Traceability:
Anonymity: Extremely low or impossible.
Anonymity: Transaction history can be traced.
Level of openness:
Anonymity: Information is completely hidden All.
Anonymity: Transparent transaction information on the ledger.
Practical example:
Anonymity: Non-custodial cash transactions.
Anonymity: Bitcoin, Ethereum transactions.
This polarization creates a paradox in blockchain: absolute transparency of Ledgers help ensure trust and prevent fraud, but that very transparency is a barrier to complete privacy. When a person uses Bitcoin, they are essentially "speaking" to the world about the amount of money they transfer and receive, they are just wearing a digital mask. However, if that mask (wallet address) is removed through forensic analysis techniques or data from exchanges, their entire financial history will be exposed.
See also: What are Trustless and Permissionless? Detailed comparison in Blockchain
Pseudonymization mechanism in public Blockchain networks: Bitcoin and Ethereum
Bitcoin, as the first blockchain, set the standard for the pseudonymous model through its unspent transaction output (UTXO) structure. When users create a Bitcoin wallet, they generate a public and private key pair. The public key is hashed to create the wallet address, an identifier that does not require any personal information (PII) such as name, address or identification number. This allows users to participate in the network freely, meeting the goal of financial sovereignty.
However, the nature of blockchain is an immutable ledger, where all transactions from the original block (Genesis Block) to the present are permanently stored and allow anyone to check. This transparency means that if a particular wallet address is linked to a real identity – for example through a purchase requiring a shipping address or through KYC (Know Your Customer) verification at an exchange – that individual's entire past and future cash flow can be tracked.
Ethereum, despite its different architecture based on an account-based model instead of UTXO, also maintains transparency. similar impersonation. In the Ethereum ecosystem, externally owned accounts (EOA) are governed by private keys and do not contain source code, while contract accounts contain executable source code. The complexity of Ethereum, with its ability to execute smart contracts and decentralized applications (dApps), leaves even more behavioral traces. Analysts can rely on user interactions with DeFi protocols, NFT markets, or “gas fee” payments to build a detailed behavioral profile of a wallet address.
Blockchain Forensic Science: Techniques to Peel Back the Impersonation Layer
The rapid growth of blockchain forensics has turned pseudonymity into a weak barrier for law enforcement agencies and security companies. Blockchain forensics is not just about reviewing individual transactions on block explorers like Etherscan or BscScan, but is a large-scale data analysis process using machine learning and artificial intelligence algorithms.
Forensic investigations typically follow a strict structure of five main stages:
Acquisition and scoping:Collection of wallet addresses and hashes related to the incident.
Preliminary tracing: Map the movement of assets across the chain and across different platforms.
Behavioral analysis: Study wallet usage patterns, transaction times and interactions with tokens to understand user habits.
Phase attribution segment (Attribution): Look for traces of identity such as reused emails, KYC details at exchanges or points of interaction with traditional infrastructure.
Documentation and reporting: Build a dossier of evidence to present to investigative agencies or courts.
One of the most important techniques in blockchain forensics is address clustering (Address Clustering). Experts at Tan Phat Digital note that modern tools use heuristics rules to determine whether various addresses belong to the same entity.
Tracking techniques and mechanisms of action:
Clustering Heuristics:
Mechanism: Group wallets based on common transaction behavior (like multi-input).
Goal: Identify wallets owned by an individual/organization.
Peel Chain Analysis:
Mechanism: Track the chain of small transactions separated from a large amount of money.
Goal: Trace the origin or destination of the stolen money Laundering.
OSINT (Open Source Intelligence):
Mechanism: Mining data from forums, social networks, IP/email leaks.
Goal: Linking wallet addresses with real identities.
Dusting Attack:
Mechanism: Sending small amounts of money to observe the merging of accounts.
Goal: Break the dispersion of user addresses.
Cross-chain Tracing:
Mechanism: Tracks the flow of funds across bridges and DEXs.
Goal: Prevents deletion of tracks across different networks.
The combination of on-chain analytics and off-chain information makes maintaining privacy on public blockchains extremely difficult. In particular, centralized exchanges (CEX) act as important "choke points" providing golden evidence for financial investigations.
See more: What is Zero-Knowledge Proof (ZKP)? ZK's Application in Blockchain
Privacy Coins: Striving for Complete Anonymity
Recognizing the vulnerabilities of pseudonymity, privacy coins were born with the goal of restoring absolute privacy by concealing all components of a transaction: sender, recipient, and amount.
Monero (XMR) is considered the gold standard in this field thanks to its adoption of a privacy-by-default mechanism. Unlike traditional blockchains, Monero integrates a complex set of cryptographic tools to cut off any traceability:
Ring Signatures: Mixes the signature of the real spender with multiple decoys taken from old transactions.
Stealth Addresses: Creates a single-use receiving address per transaction.
Ring Confidential Transactions (RingCT):Uses Pedersen commitments to hide the amount of money being transferred.
Zcash (ZEC) again approaches privacy through an optional privacy model using zk-SNARKs, allowing users to choose between transparent transactions (t-address) and protected transactions (z-address).
Features of typical privacy coins:
Monero (XMR):
Technology: Ring Signatures, Stealth Addresses, RingCT.
Status: Completely anonymous by default.
Zcash (ZEC):
Technology: zk-SNARKs (Zero-Knowledge Proofs).
Status: Anonymous option (Shielded transactions).
Dash (DASH):
Technology: CoinJoin (PrivateSend).
Status: Anonymity option (Medium level).
Pirate Chain:
Technology: zk-SNARKs.
Status: Forced anonymity (Shielded only allowed).
This anonymity provides strong protection but also creates a direct confrontation with regulations anti-money laundering (AML), leading to the mass delisting of privacy coins from major exchanges in 2024 and 2025.
Next Generation Secure Blockchain Platforms: From Privacy Coins to Privacy Platforms
During 2024-2026, the blockchain privacy sector made an important shift: from focusing solely on privacy cryptocurrencies to privacy platforms Privacy platforms support smart contracts.
Aztec Network emerges as a Layer 2 solution on Ethereum that uses zk-rollups to provide programmable privacy. Meanwhile, Secret Network and Oasis Network use a hardware-based approach called Trusted Execution Environment (TEE). This evolution enables more complex usage scenarios such as secure DeFi, secure digital identity and enterprise payments while ensuring optimal data security to the standards that Tan Phat Digital always upholds.
Legal landscape and compliance challenges: MiCA, FATF and practice in Vietnam
The development of security technologies has prompted strong responses from global regulatory agencies. The European Union's Markets for Crypto-Assets (MiCA) Regulation is an important milestone, with Article 76 prohibiting the listing of assets with built-in anonymity unless the user is identifiable.
In Vietnam, the legal landscape is still in a "legal void". While it is not prohibited to own cryptocurrencies as personal property, using them as a means of payment is against the law. The ChainTracer project is a good example of applying technology to solve these challenges in the domestic market.
Summary of impacts from regulations and organizations:
FATF (Travel Rule):
Content: Requires exchanges to share sender/receiver information for transactions above certain thresholds determined.
Impact: Reduces the anonymity of custodial wallets.
MiCA (EU):
Content: Prohibits listing of assets with built-in anonymity functionality unless the user is identified.
Impact: Forces exchanges to delist Monero, Zcash.
Male:Content: Not recognized as property but prohibited from being used as a means of payment.
Impact: Creates major legal risks for participants.
The dilemma triangle: Privacy - Compliance - Usability
Blockchain developers are currently facing a "dilemma triangle" New trilemma: how to balance Privacy, Compliance and Usability. Protocols like Cloak on Scroll are trying to solve this problem through "de facto privacy", allowing selective disclosure of information to regulators when necessary.
Iconic cases: Lessons in the failure of trust in anonymity
The history of cryptocurrency is full of examples of individuals who believed they were completely anonymous but still ended up caught in the crosshairs of the law like the Silk Road case (James Zhong), AlphaBay (Alexandre Cazes) or BTC-e (Alexander Vinnik). These cases confirm a truth: in a public and eternal ledger system, anonymity is a temporary state, while transparency is eternal.
10 Typical Case Studies: Practical lessons on tracing and the collapse of anonymity
Here are 10 classic cases that have proven that blockchain is not an absolutely safe haven for financial criminals, compiled by Tan Phat Digital:
Bitfinex Hack (Lichtenstein & Morgan): Ilya Lichtenstein stole 119,754 BTC from Bitfinex in 2016. Despite using many complex money laundering techniques (such as chain jumping, using mixers), the FBI recovered about 94,000 BTC (worth $3.6 billion at the time) in 2022 after gaining access to files containing private keys on cloud storage.
Silk Road & James Zhong: James Zhong hacked over 50,000 BTC from the Silk Road black market in 2012 and hid them for 10 years. In 2021, IRS-CI traced the money flow and found a cold wallet containing the keys hidden in a tin box under the wooden floor and in a popcorn tin in the closet of Zhong's house.
Colonial Pipeline Ransomware: After the cyber attack in May 2021, this company paid 75 BTC ransom to the DarkSide group. The FBI traced the money flow through the public ledger and quickly recovered 63.7 BTC by possessing the private key of the receiving wallet.
Tornado Cash (Roman Storm & Alexey Pertsev): This Mixer is accused of facilitating money laundering of more than 1 billion USD, including assets from the Lazarus group (North Korea). Pertsev was convicted in the Netherlands in 2024, while Storm faced charges in the US in 2025 for operating an illegal money transfer business.
AntEx Project (Vietnam): City Police. Hanoi has prosecuted a fraud case related to the AntEx cryptocurrency project. A team of experts from the ChainTracer project assisted in modeling cash flows, identifying suspicious wallet clusters, and collating KYC data from exchanges to clarify the identities of subjects.
AlphaBay (Alexandre Cazes): The black market that succeeded Silk Road was busted in 2017. Alexandre Cazes was discovered due to an elementary error: using personal email in automatic notifications of the AlphaBay system, helping investigators directly link the administrative account with the real identity.
BTC-e exchange (Alexander Vinnik): This exchange has processed more than 4 billion USD, mostly "dirty" money from hacks. Vinnik was arrested in Greece in 2017. The case shows that even without KYC, intersections with the traditional financial system are still loopholes for traceability.
PlusToken Ponzi Scheme: A 2 billion USD fraud in China (2018-2019). Even though the subjects transferred money through thousands of wallets and OTC markets, Chinese authorities still tracked down and arrested key subjects, although a large part of the assets still cannot be recovered due to dispersion.
OneCoin Ponzi: Taking advantage of the name "revolutionary blockchain", OneCoin defrauded billions of dollars. The money was laundered through traditional banks and converted to Bitcoin, proving that even "fake" cryptocurrencies leave traces in the banking system.
Samourai Wallet: The founders of this Mixer wallet pleaded guilty to charges of conspiracy to operate an illegal money transfer business involving more than $200 million in dirty money in 2025, showing the government's efforts to target the tools that facilitate anonymous support.
10 Frequently Asked Questions (FAQs)
1. Is Bitcoin truly anonymous? No, Bitcoin operates in a form of pseudonymity. Your real identity is not visible on the ledger, but your wallet address and entire transaction history are public for anyone to see.
2. How do authorities trace Bitcoin transactions?Law enforcement agencies use techniques such as clustering, wallet behavior analysis, open source information mining (OSINT) and especially KYC data from centralized exchanges to link wallet addresses with real users.
3. Why is Monero considered more anonymous than Bitcoin? Monero uses default technologies such as Ring Signatures to hide senders, Stealth Addresses to hide recipients, and RingCT to hide transaction amounts, making analysis of money flows on the ledger impossible for conventional traceability tools.
4. Is using anonymous cryptocurrency legal in Vietnam? In Vietnam, cryptocurrency (including anonymous types) is in a "legal vacuum". The law does not prohibit owning them as personal property, but strictly prohibits using them as a means of payment for goods and services.
5. How does Zcash differ from Monero in terms of privacy? Zcash offers optional privacy. Users can choose transparent transactions (t-address) or protected transactions (z-address) using zk-SNARKs technology. In fact, the majority of transactions on Zcash today are still transparent transactions.
6. How does the EU's MiCA regulation affect anonymous cryptocurrencies?The MiCA regulation (which comes into full effect from the end of 2024) prohibits exchanges from listing cryptocurrencies with built-in anonymity functions unless they can determine the holder's identity and transaction history. This has led to a wave of delisting coins like Monero in Europe.
7. What is a "dusting attack" and how dangerous is it for privacy? This is a technique of sending extremely small amounts of coins (dust) to many different wallets. When users collect these "dust" amounts to transact, they unintentionally link those wallets together, helping investigators uncover the relationship between wallet addresses that were thought to be separate.
8. What problem do platforms like Aztec or Secret Network solve?Different from coins that are just for remittance, these platforms support "programmable privacy" through smart contracts. This allows building DeFi, voting or digital identity applications where the computational data inside is completely secure.
9. How does Layer 2 privacy on Ethereum work?Solutions like Aztec act as a "secure tunnel" on Ethereum. Users deposit money into this Layer 2, perform private transactions inside and then withdraw, making it difficult to trace from the deposit point to the withdrawal point on Layer 1.
10. What is the future of privacy in Blockchain? The future trend is "actual privacy" or "auditable privacy". Instead of absolute anonymity, new technologies allow users to keep information secret from the public but selectively disclose it to regulators to comply with the law.
Blockchain is not a completely anonymous tool; it is an extremely transparent pseudonymization system. This distinction is fundamental to all economic and management activities in the digital asset space. According to expert opinion from Tan Phat Digital, in the future, the battle between privacy and surveillance will continue to escalate with the popularity of zk-proofs technology to provide "responsible privacy".
Blockchain will no longer be a "Wild West" of anonymity, but will become a sophisticated financial infrastructure, where privacy is intentionally programmed to serve individual freedom as well. and the stability of the global financial system. The transparency of blockchain, initially considered the enemy of privacy, may eventually become the best tool to protect it through modern mathematical proof mechanisms.
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