Questions tagged [sha-512]

SHA-512 is part of the SHA-2 family of hash functions with a 512-bit output and a 256-bit security level.

Filter by
Sorted by
Tagged with
62
votes
5answers
50k views

SHA-512 faster than SHA-256?

I'm getting this strange result that SHA-512 is around 50% faster than SHA-256. I'm using .net's SHA512Managed and SHA256Managed ...
3
votes
1answer
713 views

Change initial hash value of SHA-512/$t$

Fips 180-4 defines under 5.3.6 how to calculate initial hash values for SHA512/$t$ for a given value $t$. Can someone explain me how the t actually affects the outcome of the procedure (which, as far ...
2
votes
2answers
2k views

HMAC-SHA-512 output randomness?

This is regarding an online roulette game that claims to be fair. Here is the explanation: Two strings are created: STRING1 = "[NONCE]:[SERVER SEED]:[NONCE]" STRING2 = "[NONCE]:[CLIENT ...
0
votes
2answers
2k views

How different is SHA-512/224 when compared to SHA-512?

I understood from the NIST SHS specifications (FIPS 140-4) that the difference between SHA-512 and SHA-512/224 the two differences are the initial hash value and the final result truncation I changed ...
7
votes
3answers
1k views

Why SHA-512/256 when we already have SHA-384?

Both of them are just SHA-512 with different IV's and truncation. What's the point of having 2 of them? (Actually we have 3 of them as SHA-512/224 is the exact same thing.)
0
votes
3answers
164 views

Why is SHA256/SHA512 not broken for shortish passwords

I don't get why SHA-256/SHA-512 hasn't been broken, at least for shortish (10-12 character) passwords It is perfectly plausible to pre-compute a password/hash-pair table using numerous very fast ...
-1
votes
1answer
71 views

Salt length in SHA-512 version of Unix crypt command

SHA-512 crypt specs reports that SHA-512 crypt uses 128bit salt. The FreeBSD/Linux password generation code builds the salt using 16 bytes random data (128bits) and then it translates the random data ...
0
votes
1answer
59 views

Is it secure to repeatedly rehash a digest to extend the digest length?

Upon reading through the source code of Rainbow, a post-quantum signature algorithm, I found a hashing function that, using SHA-512, produced a variable length digest. This was achieved was by ...
0
votes
0answers
28 views

What security vulnerabilities exists when encrypting then hashing to be able to search values in database?

im trying to find a good way to allow searches against encrypted data in the database. Lets say i want to encrypt phone numbers, if its encrypted securely i cant search against phone numbers directly ...
2
votes
1answer
60 views

SHA3-512 similar message digest

How is it possible to find a similar message-digest for SHA3-512 for the first 80 bits or so? There was a Q/A on this site where the answer stated that 80 bits that $2^{42}$ computations are required. ...
-2
votes
1answer
141 views

Are there any crypto hash implementation beyond 512 bits of output?

My question is this: Are there any crypto hash implementations beyond 512 bits of output? Could you give me the link? Thank you so much for your time. Greetings.
1
vote
1answer
69 views

Is it possible to affect the output of HMAC w/ SHA-512 by providing it with a custom message?

Consider an HMAC algorithm that uses SHA-512 with an unknown private key. Is it possible to affect its output, either partially or totally, by providing it with carefully crafted messages? For the ...
0
votes
0answers
40 views

What can be deduced/extracted from this local hash extracted from Windows Machine?

I'm new to cryptography. I've been experimenting with getting Windows hashes to see whether it's possible to reverse engineer. The following hash is what I got from my test laptop. What can you ...
6
votes
2answers
3k views

Why might SHA-384 throughput be lower than SHA-512 throughput in hashcat and more secure?

I found a hashcat benchmark results in the internet: hashcat results: SHA-384 is 17065.4 MH/s SHA-512 is 17280.3 MH/s Why does SHA-512 take less time? SHA-512 is longer and I thought it therefore ...
14
votes
4answers
3k views

Is there a way to use bcrypt with passwords longer than 72 bytes securely?

From my understanding BCrypt truncates the password to 72 bytes. If a password is longer than 72 bytes, what is a way to store that password using bcrypt securely without compromising it? Or is this ...
2
votes
1answer
2k views

FIPS-Compliant SHA2

I want to use SHA-512 for hashing in a system that must be FIPS-compliant. When I look at the FIPS 140 list of approved providers, I don't see SHA from any provider as being an approved algorithm, I ...
1
vote
1answer
282 views

Is it possible to find the key of an HMAC-SHA-512 given the input and the hash output?

Is it possible to find the key of an HMAC-SHA-512 given the input and the hash output? If so, what algorithm if any prevents this? I'm working on a simple E2E communication system between two self-...
1
vote
1answer
90 views

Can I find a specific SHA512 for an partially-known string?

I have a plain text string "I-like-drawwing", and this string has a SHA512 value, assume the SHA512 is "aabbcc". Then I show SHA512 "aabbcc" to my friend and say: "this is SHA512 for my string, and ...
0
votes
0answers
80 views

Combining Hashes - NTLM and SHA

i have been recently learning about different types of hashing and the encryption/decryption methods of such hashes. Im currently trying to find the preimage of this hash i have been given as a ...
1
vote
2answers
348 views

521-bit ECC keys are the same strength as RSA 15,360-bit keys

521 bit ECC uses key sizes 7.5 times smaller than the RSA standard while offering encryption that is magnitudes more secure. An RSA 2048-bit key's secure enough for banking, but a 521-bit ECC key is ...
2
votes
2answers
579 views

Sha-512 understanding padding problem

I don't understand how to append the length of 128 bits exactly? First, we pad bits to make the length ($n*1024-128$) but then I need to append 128 bit of the plain text length. I find the problem to ...
0
votes
1answer
137 views

How safe is my method

I'm building a website. I have an API which takes 2 parameters: delete_user(user_id, hash). And there is method to evaluate hash using SHA512: ...
-2
votes
1answer
4k views

Decrypting SHA-512

I was recently solving a CTF problem and it involved a shadow and passwd file. I got to know the username easily but I am unable to find the password since it is SHA-512 hashed. My doubt is that when ...
1
vote
1answer
136 views

enhanced hash password in bcrypt for nuGet library

Why do we use EnhancedHashPassword in nuGet library and chose a SHA algorithm like this? ...
0
votes
1answer
391 views

What is the probability of a collision in SHA-512 when the input is 512 bits of data

Although this question is strongly related to my previous question, it's certainly not the same: Suppose the input of SHA-512 is 512 bits of data (so exactly the same size as the output). If I would ...
1
vote
2answers
2k views

Are there parts of a SHA-512 hash that occur more often then others?

Suppose I have a 'begin' password that I can remember. I calculate it's SHA-512 hash, transform it to base-64 and check if it has a least 1 lowercase, 1 number, 1 capital, and 1 sign. If this is not ...
1
vote
2answers
241 views

PBKDF2 with SHA-256/512 for low entropy input?

Is there any reason to use something stronger than SHA-1 with PBKDF2 if my input is fairly low entropy? I.e. if the passwords being hashed are only about 30-bits of entropy. I can't find it now, ...
2
votes
1answer
102 views

How to compute initial buffer of SHA-512?

I'm reading Cryptography And Network Security of William Stallings. In the SHA-512 section it is said that there is a 512-bit buffer is used to hold the intermediate and final result and every 64-bit ...
3
votes
1answer
2k views

Standard hash function of Linux

So I went through my /etc/shadow file in Linux and discovered that my passwords were stored in SHA-512-based crypt ('sha512crypt') mode, so SHA-512. But why? I mean ...
11
votes
3answers
2k views

Is deriving the IV from the password secure?

I came across an encryption scheme to encrypt files with AES-256. You can see the initialization of the decryption routine below: ...
0
votes
1answer
147 views

Finding and matching SHA512 Unsalted Hash

We are given a list of possible strings, there are $32^{16}$ ($=2^{80}$) to be exact. We also have the unsalted SHA512 of the original target string. How long would it take to go through those ...
11
votes
4answers
2k views

Why is SHA-512 limited to an input of $2^{128}$ bits?

Both SHA-384 and SHA-512 are limited to an input size of less than $2^{128}$ bits. Considering SHA-512 has a higher output size, couldn't it include more input data?
0
votes
2answers
2k views

19 out of 24 words of BIP39 passphrase (brute-force last 5?)

I have managed to lose 5 words of my 24 word Ledger Nano S recovery phrase. I have words 1-19 but I am missing words 20-24. I have significant holdings on the wallet so would very much like to recover ...
3
votes
1answer
87 views

What is SHA-512's input space, taking into account variable message size?

The SHA-512 hash function accepts any message from a single bit to $2^{128}$ bits. Because the function takes into account the message length, I can't just represent every message as a $2^{128}$-bit ...
3
votes
2answers
179 views

What is the proof that a hash output contains random binary numbers

I have heard quotes by many that a SHA-512 hash output is random. Does anyone know what method was used to come to this conclusion? If it is not randomized, how could that be shown?
1
vote
1answer
703 views

How does converting character set affect hash entropy?

Does mapping a large character-set hash onto a small character-set hash lower entropy for a fixed size substring? I'm writing a python app that involves generating passwords for websites. During the ...
1
vote
2answers
337 views

Hash collisions in sha512 hash of secp256k1 public keys

For a sha512 hash of a secp256k1 public key, how many other public keys could generate that hash? I would assume zero since the key size is equal to the hash length (secp256k1 public keys are 64 bytes,...
1
vote
2answers
620 views

Can i generate a SHA512 hash if i know the SHA256 hash of some unknown data?

if the SHA256 Hash of some unknown data is known ! Can i find the SHA512 of that unknown data ?
3
votes
2answers
21k views

What is the length field in SHA-512 padding?

If I am using SHA-512 on a message and need to determine the padding field and length field, how do I determine the length field? I think I understand the padding, but not the length field. For ...
0
votes
1answer
173 views

Is there any Corelation between the SHA256 and SHA512 hash of the same data?

Is there any Corelation between the SHA256 and SHA512 hash of the same data ?
1
vote
1answer
594 views

Which is more secure for hashing: SHA512 or BCrypt with the same salt reused over and over?

Setting aside questions of if BCrypt should even be used in this way, I was just wondering which one would be more secure hypothetically. If you want to know why I don't just use random salts as per ...
4
votes
1answer
478 views

Worth taking performance hit of HMAC to gain additional security?

It seems like SHA-512 truncated to 256 bits is usable as a MAC [1]. The advantage is that it's ~50% faster than HMAC-SHA-256 on 64-bit CPUs and ~50% faster than HMAC-SHA-512 on short inputs. (My use ...
1
vote
1answer
83 views

Strength of Sha512Ctr PRNG

What is the cryptographic strength of sha512ctr when I simply concatenate a counter and 64 bytes from a cryptographic random number generator (in this case RNGCryptoServiceProvider from .net), and ...
2
votes
1answer
137 views

Calculate new hash from old hash + appended string

If I have a hash of some string in the form: hash(UNK + "known"), Is there a way to calculate the hash of (UNK + "known" + "append"), given the hash of the original value? Specifically I'm asking ...
56
votes
2answers
19k views

Is truncating a SHA512 hash to the first 160 bits as secure as using SHA1?

I am from a web development background (I don't know an awful lot about cryptography or how the algorithms themselves work), so I am asking this question in simple terms. Consider a hash of the word '...
-1
votes
4answers
4k views

Size of A Hashed String Using SHA-512

When hashing a messages of size of n, does the SHA2 algorithm always produce the same sized hashed value? The reason I am asking is that I am building an OAuth 2.0 ...
0
votes
1answer
350 views

How long would it take to crack a double hash if salt and final hash are public?

I have a hash of a file $H_1$ and then I add salt and rehash it: $H_2$. I make my $H_2$ and salt public and I use my $H_1$ as a password. How long would it take for this to be cracked with someone ...
0
votes
1answer
276 views

Hashing user password without database to store salt

I am building an Android app that will run purely locally on the user's device, no servers. It has a database that I want to encrypt with the user's password, which requires a 64 byte key. I've ...
0
votes
2answers
2k views

VeraCrypt a weak point [closed]

Biggest flaw in VeraCrypt(or other Encryption programs) is Hash Algorithm. VeraCrypt hashes (SHA,Whirlpool,Streebog) it is the only point where can break an encrypted disk. Because break algorithm (...
1
vote
2answers
15k views

Is it possible to break SHA-512?

Is it possible to break the SHA-512 hash algorithm? Are there any successful attacks out there?