1
vote
1answer
38 views

How difficult it is to solve a salt if knowing the original data and the hash output that uses the SHA-2 algorithm

I am reading the documentation for Kentico where it describes using hashes to validate query strings ...
2
votes
2answers
122 views

Does sending two different hashes of the same password reduce security?

I'm updating a login system. The password is sent to the server as SHA512(password + long_string). I want to switch this to something like SHA512(username + password) in the future. By doing that I ...
1
vote
1answer
326 views

Reversing a block hash of SHA-1 with known Plaintext?

Is it possible to reverse the hashing of a block in a Datastream fed to an SHA1 if the plaintext for that block is known? If it is not possible (which I assume) does it make attacks to retrieve the ...
2
votes
1answer
714 views

Are there sha 512 rainbow tables available? [closed]

Are there sha 512 rainbow tables available for download or what kind of dimensions and processing power would be required to generate them?
4
votes
2answers
618 views

Rounds of MD5 and SHA512 Hashing Algorithms

What is the exact number of rounds employed by the MD5 and SHA512 hashing algorithms? According to various sources, the SHA512 hashing algorithm employs a total of 80 rounds ...
5
votes
2answers
124 views

What is the meaning of the term “simple string” for the SALT string in Unix crypt using SHA-256 and SHA-512?

In Unix crypt using SHA-256 and SHA-512 the author, Ulrich Drepper, introduces the SALT string as the following (highlight by me): For the SHA-based methods the SALT string can be a simple string ...
1
vote
1answer
281 views

what does GUID have that a whirlpool, md5 or sha2 hash dont

I'm trying to understand the use of GUID and what has always left me wondering is what's so special about them that I should consider using them instead of rolling my own type of unique id. In other ...
5
votes
4answers
963 views

Gold Standard for password hashing

I've developing a web application that will be dealing with highly sensitive information and I want to ensure the hashing of passwords is gold standard. Ideally I'd go for per-user salted SHA512 ...
0
votes
3answers
361 views

Key stretching an hash

if I implement an function which hashes the first half of my password with MD5 and the second half with SHA2 and MD5. Is there a security issue when I put these two hashes together to a 64 character ...
22
votes
4answers
3k views

What is SHA-3 and why did we change it?

On the 2nd of October NIST decided that SHA-3 is the new standard hashing algorithm, does this mean we need to stop using SHA-2 as it is not secure? What is this SHA-3 anyway?
1
vote
0answers
114 views

Recomended hash algorithm [duplicate]

Possible Duplicate: How to securely hash passwords? Do any security experts recommend bcrypt for password storage? What would you choose between: PBKDF2 SHA256 (270,000 iterations) ...
1
vote
1answer
998 views

How many possibilities can today's computers check (per second) in a SHA512 hash of a 50-byte-long random entry? [closed]

The problem I want to avoid is "brute force" attacks against a database. So if I add a 50-byte-long cryptographically random salt to my information (which I don't need to retrieve, just its hash) - is ...