Tagged Questions
2
votes
1answer
63 views
Why is H(message||secret_key) not vulnerable to length-extension attack?
Given a Merkle-Damgård hash function $H$, I know that an attacker can forge a message protected by a MAC computed as $H(\textrm{secret_key}||\textrm{message})$.
Why can't he perform the same ...
0
votes
1answer
51 views
length extension attack on an MD5 hash of a text file of about 10K Bytes?
How much computing time on a typical desktop computer would it take to find a new length and new data to extend a text file of about 10K Bytes with a given MD5 hash?
7
votes
2answers
620 views
understanding a length extension attack
I have been trying to understand exactly how a length extension attack works on SHA-1. I'll detail below what I've understood so far, so that I can convey my understanding of the same and hopefully ...
6
votes
1answer
553 views
In which situations is a length-extension attack a problem?
A lot of hash functions, including the SHA-2 family(but not the SHA-3 candidates and SHA256d) are vulnerable to length extension attacks. But when is this property a problem?
I guess certain naive ...
3
votes
2answers
153 views
Is a random length-extension worth the effort?
I'm conceiving an application that uses cryptographic tools and concepts for securing data. I know that's difficult and risky, therefore I prefer to ask around before implementing anything.
When ...
