Linked Questions

27
votes
2answers
4k views

What are recommended, general strategies to start block-cipher design and/or analysis?

I (and many others for that matter) have always been fascinated by the inner workings of the modern building block of cryptography: block ciphers. Now, the ressources on the "black art" of design and ...
18
votes
2answers
3k views

How is encryption broken today?

There are often articles in the news that state that a certain country or hacker has been able to decrypt/hack highly protected systems: Some examples are the Lockheed Martin RQ-170 Sentinel that was ...
10
votes
3answers
1k views

Stopping timing attacks on AES: Why is it important to prevent the OS from interrupting the AES computation?

I read the paper Cache-timing attacks on AES (by Daniel J. Bernstein), but I don't seem to understand everything. The author dedicates a long section on how to prevent the OS to interrupt an AES ...
7
votes
1answer
4k views

Is AES still secure considering all this NSA/Snowden scandal? [duplicate]

Im trying to understand if nowadays using AES is secure or not, after reading some arguments on Schneier’s blog (to be more exact, a comment to “The NSA Is Breaking Most Encryption on the Internet”) ...
9
votes
2answers
1k views

Why are side channel attacks such as SPA/DPA/ CPA based on the AES SubBytes routine?

I have three questions about AES related to side channel attacks: Why are side channel attacks such as CPA related to the non-linearity of the SubBytes routine within AES? What is the difference ...
3
votes
2answers
781 views

Is there a real purpose to use Twofish, Serpent or Threefish instead of AES?

I am wondering if other ciphers like Serpent or Twofish or even Threefish have really an use in real life, because AES seems to be very efficient in most situations. But for example TrueCrypt or ...
2
votes
1answer
2k views

Side Channel Attacks

How to make cipher resist against Side channel Attacks. Specially Timing Attack, Cachet Timing Attach, Simple/ Differential Power Analysis. Uptil now it seems all Standard Algorithms like AES, ...
3
votes
2answers
358 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 ...
1
vote
1answer
1k views

Defence against timing attacks

I know this is a difficult subject but would a good defense against timing attacks be not sending a message if the decryption or authentication fails? So if the attacker provides a wrong HMAC for ...
1
vote
1answer
198 views

How secure is AES in a critical situation?

So this one is a tinfoil-hat question. It is 99 % theoretical. So we assume that I am someone who stores highly confidential information. Maybe super secret stolen goverment stuff. And I get caught ...
1
vote
2answers
100 views

Encryption using deterministic CSPRNG as secure as CSPRNG

As a beginner it seems that a scheme derived from a CSPRNG should be as secure as that CSPRNG. Is this a correct assumption? Are there restrictions or known special cases? A rough outline would be: ...