1
$\begingroup$

There are lots of attacks which are on reduced block ciphers. There are practical attack on five rounds of AES-128five rounds aes broken in six minutes. I was just wondering if there is any practical application of reduced rounds of AES where less than 10 rounds are used.

Improve this question
$\endgroup$
6
  • 1
    $\begingroup$ Why there should be, that will be non-standard and insecure. AES quite fast and can be found in some hardware, too. $\endgroup$
    – kelalaka
    Feb 20 '20 at 6:26
  • $\begingroup$ 4 rounds of AES make a good 128-bit mixing function $\endgroup$
    – Richie Frame
    Feb 20 '20 at 7:59
  • $\begingroup$ Reduced rounds version of AES (or other cryptographic primitives) are usually used to mount a practical attack and show research results. Of course the complexity of the attack makes it infeasible on the full AES $\endgroup$
    – ddddavidee
    Feb 20 '20 at 8:14
  • $\begingroup$ I didn't watch the video yet, but maybe a reduced round AES is mentioned in Jean-Philippe Aumasson's talk "Too much crypto" at this year's Real World Crypto. You can watch it by following "The link for live streaming" on rwc.iacr.org/2020/program.html and then scrolling down in the left window "Program" to "Symmetric Cryptography II" and click it. $\endgroup$
    – j.p.
    Feb 20 '20 at 8:20
  • $\begingroup$ @kelalaka i just wanted to know if there is any use of less round aes. $\endgroup$
    – Radium
    Feb 20 '20 at 10:08
1
$\begingroup$

There is not much use for reduced-round AES as a block cipher per se. AES has been carefully designed to provide appropriate security margins and 20 years of cryptanalysis show that they are just right - reducing the number of rounds would make it potentially susceptible to attacks.

On the other hand, the single round function is a very useful transformation that provides good mixing and other provable properties. Moreover, widespread hardware support for the round function (like AES-NI instructions and similar) makes it attractive from the performance point of view.

A good example is a lightweight hash Haraka designed for short-input hashing that uses AES round function.

Improve this answer
$\endgroup$

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.