Linked Questions

18 votes
2 answers
24k views

What is the MD5 collision with the smallest input values?

I am interested in MD5 collisions for small input messages. The collision examples given at http://www.mscs.dal.ca/~selinger/md5collision/ show two different strings, where only a tiny amount of data ...
Peter's user avatar
  • 291
9 votes
3 answers
4k views

Are there MD5 collisions for inputs of different length?

There are many examples of MD5 collisions (some of them can be found here Are there two known strings which have the same MD5 hash value?). But as far as I know two inputs should have the same length ...
demonplus's user avatar
  • 191
2 votes
1 answer
3k views

Length Extension attacks in SHA1 and MD5?

From my understanding on the internet about length-extension attack, I have understood that hash(secret_key|known_data) can be exploited to produce hash(secret_key|known_data|appended_data) even ...
user173379's user avatar
0 votes
2 answers
1k views

Creating UID's using hash functions - most appropriate hashing algorithm?

I have circa 1 million datapoints, each with a unique integer ranging from 6 to 24 digits: ...
Babra Cunningham's user avatar
2 votes
1 answer
553 views

How strong if I combine two hash functions, such as MD5(SHA256(input))?

If I try to do MD5(SHA256(input)), what is the strength of this so-called double hashing approach? Is it as strong as SHA256, or as strong as MD5, or as strong as ...
Neil Niu's user avatar
2 votes
1 answer
524 views

How secure is MD5 for one way authentication?

I have a server S1 with an Private String (PS) as an identifier shared with a server S2. Every 10 min S1 publish the hash value of PS+the current time which is used as public identifier (PI). Every ...
user3235881's user avatar
1 vote
1 answer
278 views

Avoiding MD5 collision with secondary partial hashes

I am trying to design a VCS like program that determines if the files are the same by comparing their MD5 hashes. Then I read about MD5 collisions here, and I wonder if I can work around that by doing ...
Allahjane's user avatar
  • 121
0 votes
1 answer
425 views

Checking encoded strings for a hash collision in Python [closed]

There is a common term used in cryptography called a hash collision. If I am reading the definition correctly on Wikipedia, this can occur if two different data values give rise to the same hash ...
JustBeingHelpful's user avatar
0 votes
1 answer
321 views

Is there an outdated or insecure hash algorithm thats output can be easily reversed back into the input?

I'm looking for a hash algorithm thats output can be reversed back into the input in a reasonable amount of time (a day or less) using a decent consumer computer. If anyone has any information on this,...
Sir Wumpus IV's user avatar
1 vote
1 answer
149 views

Could multicollisions be used to mine large amounts of cryptocurrency?

I'm reading about hash functions at the moment, and in the book I'm reading there's a section on multicollisions. Specifically, using a 2-collision to find $2^N$ collisions in $N2^N$ time. If, ...
Radvylf Programs's user avatar
0 votes
0 answers
303 views

How to create two partly similar plaintexts with same MD5 hash value?

The problem I'd like to solve looks like this: There are two plaintexts which differ in length and letters, but contain a few common strings. The first few words and the last few words are the same, ...
user312442's user avatar
0 votes
0 answers
165 views

Is md5(x) xor md4(x) collision proof?

Suppose I have the following hash function: $\newcommand{\md}[1]{\text{md#1}} \newcommand{\H}{\text{H}}$ $$\H(x, y) = \md{5}(x) \oplus \md{4}(y)$$ How can I prove it's collision proof? I tried to ...
MyNick's user avatar
  • 101