3 ms·
The OP's problem of proving when a message is encoded is a tractable subset of 'prove X is not lying'. If you're not concerned about the actual author of a mes
by systoll 6y ago
The OP's problem of proving when a message is encoded is a tractable subset of 'prove X is not lying'.
If you're not concerned about the actual author of a message faking its timestamp, you can just do public-key encryption, and write the date in the message.
- qsort 6y agoIf you combine public key crypto with parent's suggestion, you get a claim of the kind: "I can prove the timestamp is correct, and you'll have to trust me that the content is what I claim it to be", which is stronger than just doing public-key crypto. It's not a solution of the full problem, but it's something that should cover most common use cases, unless you have pretty weird requirements.