BlockSec

BlockSec is a blockchain security and compliance company founded in 2021 in Hong Kong. It was built by security academics: co-founders Zhou Yajin and Wu Lei both hold PhDs from North Carolina State University and are professors at Zhejiang University, where they conducted blockchain security research from 2018 onward. Both previously worked as security researchers at Qihoo 360, one of China's largest cybersecurity firms. That academic lineage shaped the company's orientation toward research-first security analysis rather than checklist auditing.

The company describes its purpose as combining security research with practical cyber defense and financial compliance, and has since grown to serve more than 1,000 clients across 50 countries. Investors include Matrix Partners, Vitalbridge Capital, and Fenbushi Capital, with a completed Seed Plus round of $8 million.

What BlockSec Builds

BlockSec's product suite spans four distinct functions: smart contract auditing, real-time threat monitoring, transaction investigation, and regulatory compliance.

Auditing. BlockSec audits programs written in Solidity (EVM chains), Rust (Solana and NEAR), and Go (Cosmos). Their process runs through four stages: scope definition, engagement setup, analysis with multiple rounds of review for complex codebases, and a signed report detailing findings by severity. The firm uses a multi-reviewer structure where independent auditors cross-check each other's findings, alongside proprietary static analyzers and AI-assisted detectors. The audit scope covers smart contract architecture, business logic, economic models, token mechanisms, permission controls, upgradeability patterns, oracle and bridge integrations, and infrastructure security.

Phalcon Security. This is BlockSec's real-time monitoring and automated attack-blocking platform. It runs 24/7 across 13 blockchain networks and uses a detection engine built on over 200 defined attack characteristics. When a threat pattern is identified, the system can trigger automatic blocking in milliseconds through multi-signature wallet integration, shifting the response model from reactive incident management to preemptive prevention. BlockSec claims a detection accuracy above 99.99% with a false positive rate below 0.0001%. Over two years of operation the platform has intercepted more than 20 attacks, preventing $20 million in potential losses according to the company.

MetaSleuth. A cross-chain fund tracing and forensic investigation tool. MetaSleuth tracks asset movement across chains, maps address relationships, and tags known entities. It is used by exchanges, regulators, and law enforcement for post-incident tracing and compliance monitoring. The platform currently serves over 500 clients, including Coinbase, Bybit, the United Nations, and the FBI.

Phalcon Compliance. An AML/CFT platform offering wallet screening, Know Your Asset (KYA), and Know Your Transaction (KYT) capabilities. In December 2025, BlockSec launched Phalcon Compliance 3.1, which introduced a search-first workflow allowing users to conduct KYT screening without pre-payment, demo-driven onboarding, or account registration. The platform covers more than 600 million labeled addresses with over 200 risk signals. BlockSec holds AICPA SOC 2 compliance and is GDPR ready; the compliance suite is designated as a trusted partner by financial regulators.

Phalcon Explorer. A transaction visualization and debugging tool covering fund flows, balance changes, account relationship mapping, MEV transaction identification, and token holding analysis.

Solana Coverage

BlockSec began extending its tooling to Solana in earnest in early 2025. In February 2025, Phalcon Security added full Solana support, bringing real-time monitoring, operational risk alerts for program upgrades and authority changes, and security risk alerts for suspicious token price movements to the Solana ecosystem. The Phalcon Explorer's transaction visualization capabilities also apply to Solana.

On the audit side, BlockSec offers dedicated Solana program audits covering Rust codebases. Their methodology examines account validation patterns, program calling structures, upgrade mechanics, multi-signature implementations, and type confusion vulnerabilities specific to Solana's account model and runtime. In October 2025, the firm completed an audit of OKX's groth16-solana program, a ZK-Email proof system combining ECDSA signature verification and zero-knowledge proofs deployed on Solana.

BlockSec has also published a multi-part educational series titled "Secure the Solana Ecosystem" aimed at guiding developers through Solana-specific security patterns, from basic program architecture to complex calling conventions and program upgrades.

Clients and Track Record

Notable audit clients include Uniswap Foundation, Compound Finance, PancakeSwap, Rabby Wallet, OKX, and Bitget. Infrastructure clients include Polygon, Filecoin, NEAR, Mantle, and MegaETH. Compliance and investigation clients span crypto exchanges (Coinbase, Bybit, Crypto.com), traditional finance (PwC), and public sector bodies including the UN, FBI, and Hong Kong's Securities and Futures Commission.

Across its audit history, BlockSec reports securing over $50 billion in on-chain assets. The firm has published more than 60 audit reports across EVM chains, Solana, and other ecosystems, with recent work spanning L2 infrastructure audits (Morph Emerald), wallet security (OKX Smart Wallet Recovery), and DEX aggregation contracts (Bitget's bgw-swap-aggregator).

Recent Developments

The December 2025 release of Phalcon Compliance 3.1 removed friction from KYT onboarding, responding to what BlockSec described as a rapidly evolving regulatory landscape in digital assets. The compliance platform's client base, which now includes both crypto-native firms and institutional and government users, reflects the company's positioning across security and financial crime prevention.

BlockSec's blog maintains active coverage of security incidents, stablecoin compliance, and regulatory developments, with recent posts analyzing the COLDCARD hardware wallet entropy failure that resulted in an estimated $91 million in losses, and the mechanics of USDT freezes tracking nearly $5.7 billion in frozen assets across roughly 9,600 addresses.