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You get the definition of "symmetric" wrong. Symmetric encryption refers to using the same key for encryption and decryption, as opposed to asymmetric, aka publ
by mehrdada 12y ago
You get the definition of "symmetric" wrong. Symmetric encryption refers to using the same key for encryption and decryption, as opposed to asymmetric, aka public-key encryption. By no means AESEncrypt and AESDecrypt are the same functions.
That said, some encryption modes employing AES, like AES in CTR mode, are based on generating a pseudo-random keystream and XORing it with cleartext to get the ciphertext. The inverse of that operation is itself, but that has nothing to do with the term "symmetric encryption". This particular case uses AES in CBC mode, which is not symmetric in that sense.
- cbsmith 12y agoThere is a difference between "symmetric key encryption" and "symmetric encryption".
- dlitz 12y agoIs there? The usual term for what you're describing is a "stream cipher" or a "streaming-mode cipher".
- zamalek 12y agoI think the objection here comes from not stating that it's AES in CTR mode. AES is not a symmetric algorithm, AES in CTR mode is.
- cbsmith 12y agoThe other poster was talking about a stream cipher... However, I'd point out that DES is a block cipher (thought it can be turned in to streaming cipher much like AES), and its decryption is encryption is with the keys in reverse order. This is how triple-DES can work as it does.