Timeline for Is it possible to find the key for AES ECB if I have a list of plaintext and corresponding ciphertext?
Current License: CC BY-SA 4.0
10 events
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| Sep 20, 2019 at 8:50 | history | edited | kelalaka | CC BY-SA 4.0 |
polish
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| Mar 11, 2019 at 21:31 | comment | added | kelalaka | @SqueamishOssifrage Yes related key attacks are not affecting a serious protocol. They are effective if the block cipher is initiated as a hash function. For Multi-target, absolutely. | |
| Mar 11, 2019 at 21:26 | comment | added | Squeamish Ossifrage | This doesn't really answer the meat of the question—does knowing many plaintext/ciphertext pairs help? The related-key setting is not relevant to any halfway serious protocols, so is not relevant here, but in the multi-target setting—which is relevant to essentially all practical protocols—the expected cost to break one of $t$ AES-128 targets is $2^{128}/t$, far below $2^{128}$; for a billion targets, the cost would be below $2^{100}$ and the time would be below $2^{70}$. (Nothing special about AES: this applies to any cipher with a 128-bit key.) | |
| Nov 12, 2018 at 3:29 | comment | added | Clockwork-Muse | @RichardJones - Note that in a straight brute force attack, knowing the plain text is only for verification - that is, knowing the plain text doesn't help in the decryption at all, and probably isn't necessary (an incorrect key is usually going to generate gibberish in at least some part of a sufficient length message). | |
| Nov 11, 2018 at 19:39 | history | edited | kelalaka | CC BY-SA 4.0 |
polish
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| Nov 11, 2018 at 19:12 | history | edited | kelalaka | CC BY-SA 4.0 |
polish
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| Nov 11, 2018 at 19:03 | comment | added | kelalaka | Short answer no. For brute-force, you need only a couple of pairs. There are attacks like biclique attack, but that requires $2^{126.2}$ operations for AES-128. You can find some other attacks at Wikipedia but you will not see they are better than biclique attack. | |
| Nov 11, 2018 at 18:59 | comment | added | Richard Jones | So even if we have millions of texts and their corresponding ciphertext using our key, it wouldn't help us to find the key? | |
| Nov 11, 2018 at 18:48 | history | edited | kelalaka | CC BY-SA 4.0 |
polish
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| Nov 11, 2018 at 18:34 | history | answered | kelalaka | CC BY-SA 4.0 |