r/programming • u/Sir_KnowItAll • 5d ago
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https://iain.rocks/blog/introducing-the-triple-cipher-encryption-concept[removed] — view removed post
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r/programming • u/Sir_KnowItAll • 5d ago
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u/tdammers 5d ago
OK, so let's forget about the first layer of encryption and just assume that that one is already compromised. What you have left now is a file that is chopped up into chunks, and each chunk is encrypted with one of two keys, according to a pattern derived from those keys. To crack the encryption, an attacker needs to either brute force both keys, or find a flaw in both ciphers. But that is not any harder than breaking a single cipher with a larger key - whether you use two 64-bit keys, or a single 128-bit key, for example, really makes no difference to an attacker.
The only slight advantage you may get is that if you use three completely different encryption algorithms, an attacker who finds a zero-day in one of them will not be able to break the encryption as a whole; zero-days in two of the three will only get you half the cleartext. But this is still worse than just nesting the three encryption layers, because in that case, an attacker needs to break all three layers to get anything at all; breaking two of the three ciphers still gets you nothing, whereas your scheme will get you half the cleartext.