3 ms·
This analysis shows again that it is difficult to roll a custom cryptographic algorithm and also that the level of security of a solution does not depend on the
by brian_herman 4y ago
This analysis shows again that it is difficult to roll a custom cryptographic algorithm and also that the level of security of a solution does not depend on the number of encryptions performed.
From the article
- 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!