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This a very good explaination of why 256 bits is enough against a brute force attack. The goal of breaking cryptographic systems is of course not brute force, b
by bajsejohannes 14y ago
This a very good explaination of why 256 bits is enough against a brute force attack. The goal of breaking cryptographic systems is of course not brute force, but to reduce the actual key space you have to search. This is frequently measured in how many redundant bits you can shave off. So for AES, we might find in the future that 256 bits isn't enough after all.
- p4bl0 14y agoActual implementations of 256 bits AES are already breakable using side-channel attacks.
- chii 14y agoso if that key size is increased, would these side channel attacks be either mitigated, or made impractical?
- p4bl0 14y agoNo that's not the way to go for countermeasures against side-channel attacks (breaking 4096 bits key in asymmetric crypto is also doable using side-channel attacks, even in the cloud [1]). Since it is a physical attack rather than a mathematical one, the countermeasures are at the physical level too: the idea is to make the cryptosystem leak less information through channel such as power consumption, computation or memory access time, electromagnetic radiation… Currently most of these countermeasures are at hardware level. [1] https://news.ycombinator.com/item?id=4865516 https://news.ycombinator.com/item?id=4865516 Edit: forgot to add reference link.