The second design. Click on the photo to go to the shop.

Here in the UK, not handing your encryption keys to the police if they ask for them is an offense. Telling them that you don’t have the key — or that the file in question is just random numbers — is not an excuse.

(If an officer demands the key to decrypt this shirt, don’t worry: this is a legal shirt. You can tell him, quite truthfully, that it shows the start of my PGP key.)