Difficulty of finding two different inputs that hash to the same value
1
vote
1answer
54 views
How hard is it to generate a partial RSA fingerprint collision?
When I use SSH to log into a new system, I get asked to verify that the fingerprint (a 32 hex digits string) of the hosts's RSA key is correct. How much if it must I actually compare (by hand/eye) to ...
1
vote
2answers
88 views
Does collision resistance stay when extending a hash function to a set domain?
Given a Cryptographic hash function $h$ for element $x$, let's extend it to sets via $H(S)=\prod_{x\in{S}}{h(x)}$. I am asking if the new hash $H$ (in domain of set) is still collision resistant?
To ...
4
votes
1answer
355 views
From hash to Cryptographic hash
After reading some excellent papers on SipHash, I understood that good non-cryptographic hashes such as MurmurHash and CityHash are not secure for MAC usage, due to a certain type of DDos attack ...
-1
votes
1answer
114 views
RSA SHA1 signature from public key
Is it possible to generate signature only from Public key. See example below where i have valid signature but what if I change hash ? Is then any way to do this?
Public key(160 bytes):
...
2
votes
0answers
148 views
Does Keccak have an eTCR mode?
On page 7 of NIST's views on SHA-3's security requirements and Evaluation of attacks, I see that, at least at this point, NIST planned on offering SHA-3 having eTCR security (defined on page 3):
...
0
votes
1answer
160 views
Hash collision resistance requirements for Lamport signatures
According to the original paper, Lamport one-time signature scheme uses two one-way functions: $F$ and $G$. The former one, $F$, is used to create a public key by hashing elements of the private key ...
3
votes
1answer
260 views
bcrypt - collision-resistance against chosen salt and work factor?
Would it be difficult to find $\:$ cost,salt,input,password0,password1 $\:$ such that
bcrypt(cost,salt,password0,input) = bcrypt(workfactor,salt,password1,input)
and $\:$ password0 != password1 $\:$ ...
1
vote
2answers
242 views
Real life collision when only using truncated hash
For MD5 two different inputs are known that produce the same 128 bit hash value. However, these inputs are artificially created for this specific purpose.
For normal, real life inputs I believe no ...
2
votes
1answer
90 views
What “Tag Length” should be used for the EAX MAC?
Since EAX is very flexible with regard to the length of the calculated MAC (what they call "tag" is the MAC value right?), and the EAX paper as well as other documentations carefully avoid suggesting ...
7
votes
3answers
1k views
What is pre-image resistance, and how can the lack thereof be exploited?
What is preimage resistance, and how can the lack thereof be exploited?
How is this different from collision resistance?
Are there any known preimage attacks that would be considered feasible?
