The CPU also contained ROM storing Microsoft private encrypted keys, used to decrypt game data. Once they have obtained that encryption key, they can decrypt encrypted data at rest. Once encrypted, only the private key of the recipient can decrypt the email. Public keys are used for encryption or signature verification; private ones decrypt and sign. It then uses the symmetric key to decrypt the file. The public key will decrypt the signed hash. Additionally they showed how to decrypt arbitrary packets sent to a client. The Bundeswehr would use it to detect, decrypt, and potentially interfere with enemy communications signals. The server will reject the very first request from the client which it cannot decrypt. Their attack against TLS can decrypt a secure HTTP cookie within 75 hours. American cryptographers built a machine that could decrypt these messages. Apple cannot decrypt this data. In order to decrypt the transmitted messages, two tasks had to be performed. There were also projects to decrypt some remaining messages using distributed computing. Krakoa manages to successfully decrypt the index, revealing the location.