Coldcard Exploit Exposes Flaws in Air-Gapped Wallets
Air-gapped Bitcoin wallets are designed to keep private keys completely isolated from the internet. These wallets take the phrase 'not your keys, not your coins' a step further by providing the highest level of security for individual crypto holders.
The Coldcard exploit has resulted in losses totaling $114 million in Bitcoin and counting. This incident highlights that even air-gapped wallets can contain critical flaws and underscores the importance of security practices beyond just keeping a wallet offline.
Air-gapped wallets, such as those made by ELLIPAL, Keystone, Foundation Devices, Blockstream, and Coldcard, are designed to be completely disconnected from online networks. However, this doesn't mean they are immune to every threat. Users must still protect their recovery phrase, verify transaction details before signing, and keep the physical device secure.
The recent events have shown that even air-gapped wallets can contain critical flaws. The Coldcard exploit was caused by a firmware build error introduced in March 2021, which reduced the randomness protecting users' private keys, making them vulnerable to attackers who could guess them or use AI to guess them more quickly.