Ledger CTO Charles Guillemet: Coldcard Seed Users Urged to Move Funds Quickly
Ledger CTO Charles Guillemet warns that users who generated seeds on Coldcard should immediately transfer their funds to other wallets. He noted that the method of fund clearing does not resemble North Korean tactics, and a second wave of larger withdrawals is expected after the public disclosure. Although approximately 73 users with Mk4 and above have security strengths that do not hold economic brute-force cracking value, there is still significant room for optimization, and the device IDs are far from random. The incident has driven hardware wallet users to quickly withdraw funds from vulnerable single-signature addresses, with funds flowing to addresses controlled by attackers. The beneficiaries are the attackers who possess weak entropy seeds, while the burden falls on holders relying on Coldcard to generate seeds. Source: Public Information
ABAB AI Insight
Charles Guillemet has long led the Ledger Donjon security lab and has previously published research on hardware wallet side-channel and secure element attacks, including PIN extraction from Coldcard Mk2 and early Mk3 secure element vulnerability analysis. His team is accustomed to pushing for industry reforms through public reports. This statement follows an on-chain event where approximately 594 BTC was cleared from about 500 single-signature addresses in a short time. The fund path indicates that attackers utilized weak entropy seeds to offline reconstruct private keys and then transferred funds in bulk, with resources flowing directly from user cold storage to new addresses, motivated by the desire to maximize extraction during the firmware RNG fallback public window. Similar weak entropy incidents occurred in 2022 with the Trust Wallet browser extension's Mersenne Twister using only a 32-bit seed, as well as several software wallet PRNG failure cases. The current hardware wallet industry is still in an expansion phase, and single-signature cold storage reliance has not yet been fully replaced by multi-signature and user entropy supplementation. Essentially, this represents a collapse of security boundaries due to a failure of technological substitution: after hardware TRNG was replaced by software PRNG fallback, effective entropy dropped from the expected 128 bits to 40-73 bits, fundamentally due to open-source code symbol parsing errors and a lack of build checks, allowing attackers to offline enumerate seeds using device metadata. ABAB News · Laws of Cognition
- When entropy is insufficient, hardware is just a shell.
- Open source accelerates discovery, but also accelerates exploitation.
- Security boundaries are determined by the weakest link.