MD5 is a hash function that is no longer considered secure from a cryptographic point of view. Therefore, it should only be used for backward compatibility.

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5
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2answers
268 views

Cost of attacking Mobile OTP with a fake server

You want to obtain a 74-bit secret $K$. There is an oracle that will provide you with the following value for several values of $T$: ...
1
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2answers
627 views

Can md5 be used for encrypting data?

I know that md5 shouldn't be used for password hashing because of collisions and possibility of making dictionary attacks e.g. using rainbow tables. But what about ...
16
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6answers
9k views

Are there two known strings which have the same MD5 hash value?

Is there an example of two known strings which have the same MD5 hash value (representing a so-called "MD5 collision")?
12
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3answers
1k views

Why does the padding in MD5 contain the message length?

I understand the need for padding in MD5. But why do we append the message length to the padding? I heard it strengthens the hash but how? Please provide an example if possible and how it applies to ...
3
votes
2answers
875 views

Is it a good idea to use bitwise XOR on a set of MD5 sums?

I have designed an SQL aggregate function in Oracle that bitwise XORs all MD5 sums of the values stored in a column. For example, if my table is: ...
20
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4answers
14k views

Best way to reduce chance of hash collisions: Multiple hashes, or larger hash?

I would like to maintain a list of unique data blocks (up to 1MiB in size), using the SHA-256 hash of the block as the key in the index. Obviously there is a chance of hash collisions, so what is the ...
4
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1answer
186 views

Is the last step of an iterated cryptographic hash still as resistant to preimage attacks as the original hash?

Considering a cryptographic hash, such as MD5 or SHA2, denoted by the function $H(m)$ where $m$ is an arbitrary binary string, there is a lot of material available that deals with potential weakness ...
7
votes
1answer
638 views

Implementation of Tao Xie and Denguo Feng's MD5 attack

It is well known that MD5 is completely broken today - however, to understand the theory behind the attacks I am looking for an implementation of the collision attacks described in the 2009 paper A ...
6
votes
4answers
378 views

Does MD5 generate 128 independent bits?

I heard that there are 128 stochastically independent bits in an MD5 output. Is that true? If so, are there any citations or proofs for that?
8
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1answer
688 views

Change in probability of collision when removing digits from MD5 hexadecimal hash values

I am aware that MD5 has a known collision vulnerability and should not be relied upon when uniqueness is required, but in the environment I am working on I only have access to MD5 hash function. ...