Take the 2-minute tour ×
Cryptography Stack Exchange is a question and answer site for software developers, mathematicians and others interested in cryptography. It's 100% free, no registration required.

Let's assume I've encrypted some text with some 24-byte key using 3DES ECB. Question: is it possible to regain the key if I have both encrypted and decrypted text? Excluding bruteforce.

share|improve this question
2  
That would amount to divination. –  fgrieu Jan 22 at 9:17
add comment

1 Answer

up vote 2 down vote accepted

It is not practically possible. There are several attacks that are slightly faster than bruteforcing $2^{112}$ key candidates, but this is only a small factor. In some sense, they are bruteforce-like, since they require $2^{113}$ smaller steps.

share|improve this answer
add comment

Your Answer

 
discard

By posting your answer, you agree to the privacy policy and terms of service.

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