Hardware wallet maker Keystone disclosed that a stolen cryptographic key could allow counterfeit devices to pass its online authenticity verification. The company said wallets shipped with the compromised old key and received after Oct. 20 require additional manual checks even if they appear valid through standard verification tools. To limit exposure, Keystone plans to destroy 18,835 unsold devices tied to the affected key. The firm urged customers who purchased older-key units to exercise caution and follow updated verification procedures before trusting device authenticity.