3 ms·
> multiple encryptions Correct me if I am wrong, but isn't AES a group, like DES? If so, encrypting twice under keys of the same strength is the same as encryp
by PeterWhittaker 4y ago
> multiple encryptions
Correct me if I am wrong, but isn't AES a group, like DES? If so, encrypting twice under keys of the same strength is the same as encrypting once, with a different key.
This is why, e.g., 3-DES uses encryption-decryption-encryption, under different keys.
- lifthrasiir 4y agoTechnically yes, but that different key might not be computed efficiently (of course no guarantee for that, but no guarantee against that as well). To my knowledge 3DES's construction is only for seamless upgrading, where putting the original 56-bit key three times gives a 3DES key.
- less_less 4y agoAES and DES are not groups. See eg https://www.cs.ucdavis.edu/~rogaway/classes/227/winter09/des-is-not-a-group.pdf https://www.cs.ucdavis.edu/~rogaway/classes/227/winter09/des....
- PeterWhittaker 4y agoAh, thank you!