0 to change electronic information or signals that were stored, written, or sent in the form of a secret code (= a system of letters, numbers, or symbols) back into a form that you can understand and use normally -- 对（电子信息）进行解码，破译，破解
A frame-theory pair is consistent if the theory only contains pairs of encrypted messages that the environment cannot decrypt.
A hedge is consistent if the hedge only contains pairs of names and pairs of encrypted messages that cannot be decrypted by the environment.
In this paper, we work with this alternative characterisation, stating that a pair of substitutions is consistent if they allow us to decrypt corresponding messages in precisely corresponding ways.
These are intuitively hedges that are reduced as far as possible, in the sense that no pair of messages in them can be decrypted using the information in the hedge.
Symmetric cryptosystems use the same key (the secret key) to encrypt and decrypt a message.
How will we be able to decrypt that information?
No doubt a penalty is available if someone refuses to decrypt the information.
Then, if he is investigated by the police, he will simply refuse to hand over the key to decrypt the files.
