Wrench attack (physical coercion)

The name comes from a well-known web comic: rather than break strong encryption, an attacker can simply threaten the owner with a wrench until they reveal the password. In practice it ranges from armed home invasions and street robberies to organised kidnappings for ransom, with victims forced to open exchange apps or sign transactions on the spot.

Such attacks have grown as crypto wealth became visible and as public data about holders spread through leaks, social media and on-chain analysis. France saw a series of kidnappings in 2025 targeting crypto entrepreneurs and their families, including a hardware wallet company co-founder, and similar cases have been reported in the United States, Asia and Latin America.

Technical defences help only partly. Keeping holdings private, not discussing them online, protecting home addresses and separating large balances behind multisig setups with geographically separate signers or time delays make an instant transfer impossible. Decoy wallets protected by a separate passphrase can satisfy an attacker, but they cannot guarantee safety, and in an attack personal safety matters more than the funds.