Encryption is compromised when the key is compromised. The key is the piece of information that distinguishes between the intended user and any intruder. The key can be stolen or it can be computed from other data. In the easy cases a replacement key will restore the original operation, In the more challenging scenarios the encryption engine will have to be adjusted, supplemented or replaced. Encryption users who can not afford to lose their encryption capability should prepare themselves for that nightmare.
Criminals steal passwords from the sick and dead and scout classified systems without.