Linked Questions
11 questions linked to/from Why don't table lookups run in constant time?
3
votes
2answers
782 views
Side-Channel Attacks in the Cloud
Let's say we have some very sensitive personal files. At all costs, we do not want any other pair of eyeballs to gaze upon them. We need these sensitive files to be secure and available.
So, we have ...
3
votes
2answers
1k views
How are these AES MixColumn multiplication tables calculated?
I'm using the mul2, mul3, mul9, mul11, mul13 and mul14 tables for the MixColumn and InvMixColumn steps in AES-128. However, I got these off some Github repository, and now I'm looking for an actual ...
4
votes
2answers
264 views
Which sub operation is more expensive in the AES encryption process?
In the AES encryption process, there are various sub-operations, like SubByte, MixColumns, ARK etc. My question is which of these operations is more expensive? In a video lecture by Dan Boneh, it is ...
4
votes
2answers
235 views
What are the issues of look-up table based implementations?
Cryptographic libraries mostly use pre-computed lookup tables to implement block ciphers. These lookup tables require large amout of memory and a series of cache miss/hit makes them vulnerable to ...
0
votes
1answer
187 views
How to make an AES implementation using lookup tables immune to cache timing attacks?
I recently made a very naive implementation of AES using lookup tables, but it's totally unsafe because of timing attacks. I am not interested in using the processor specific instructions for AES, ...
6
votes
1answer
221 views
Does a masked look-up table prevent cache timing attacks?
When applying the boolean masking countermeasure to a cipher which uses an S-box $S$, a way to handle this nonlinear operation is to recompute a new S-box $S'$ such that $S'(x \oplus r_{in}) = S(x) \...
2
votes
1answer
140 views
Is AES without T-Tables nor S-Box resistant to side-channel?
T-Tables and S-Boxes are prone to side-channel attacks, is an implementation without any lookup tables resistant to side-channel ? In this answer, https://crypto.stackexchange.com/a/63520/80926, the ...
7
votes
0answers
178 views
How to implement arbitrary s-box in a side-channel-free way in C?
This could be a question for CodeReview.SE, but I thought it might require non-trivial cryptographic knowledge to merit it on-topic here.
The C language is chosen as it's a common language for ...
1
vote
1answer
127 views
Is AES S-Box resistant to side-channel attacks?
I know that implemntations with T-tables such as Golang's are prone to side-channel attacks, but is AES's S-Box wihtout any additional table also insecure ?
0
votes
0answers
56 views
How to prevent cache timing attack on table lookup AES implementation?
I've been trying to find a solid method to prevent cache timing or other possible side channel attacks on an AES implementation, that uses lookup tables for S-box substitution.
I realize that there ...
0
votes
0answers
49 views
How does a cache timing attack work on AES with lookup tables?
I was trying to make a software only implementation of AES (Rijndael). At first I was able to implement it using table lookups for the Galois field multiplication and also for the SBox, but, I really ...