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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.

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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: ...
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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 ...
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SHA512 faster than SHA256?

I'm getting this strange result that SHA512 is around 50% faster than SHA256. I'm using .net's SHA512Managed and SHA256Managed ...
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1answer
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enhanced hash password in bcrypt for nuGet library

Why do we use EnhancedHashPassword in nuGet library and chose a SHA algorithm like this? ...
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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 ...
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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 ...
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131 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, ...
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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 ...
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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 ...
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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 ...
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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: ...
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1answer
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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 ...
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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?
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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 ...
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1answer
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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 ...
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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?
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1answer
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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 ...
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2answers
1k views

HMAC-SHA512 output randomness?

This is regarding an online roulette game that claims to be fair. Here is the explanation: Two strings are created: ...
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190 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,...
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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 ?
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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 ...
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1answer
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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 ?
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1answer
267 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 ...
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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 ...
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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 ...
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1answer
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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 ...
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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 '...
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4answers
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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 ...
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1answer
165 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 ...
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Hash-Then-Encrypt or Encrypt-the-Hash?

My question is would it make any difference if I use SHA3 and hash a block of data and then encrypt it using RSA is most secure to do the reverse? The question is about Site-To-Site transmission ...
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1answer
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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 ...
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2answers
992 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 (...
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11k 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?
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Which attacks are prevented by the different initial hash values for SHA-2 with truncated output?

NIST specified SHA-2 hash functions with truncated output. Those hashes use different initialization values than SHA-256 or SHA-512. SHA-224 is based on SHA-256. SHA-384, SHA-512/224 and SHA-512/256 ...
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Why is SHA2 used for file verification if it's susceptible to length extension attacks?

Am I misunderstanding length extension attacks, or is there some different reason, or is it really a bad idea to use SHA2 for file verification? If the answer is that it's really a bad idea, would ...
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1answer
801 views

Which algorithm should be used to replace SHA512withRSA? [closed]

We are working on the web application that is basically generating a self-signed certificate during the installation. It's a Java based app and for generation of the certificate we are using ...
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1answer
270 views

Safety of having many passwords hashed with the same salt?

I'm working on a web application where passwords must be hashed on the client before it can be send to the server. This is because the user's raw password is used for cryptography purposes and can't ...
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2answers
287 views

Is it possible to generate an infinite number of collisions given an infinite amount of strings?

Let us assume that we have a string $w$ such that it belongs the set $C$, where every member of $C$ is not null, and contains every string of characters that can be permuted (numbers, letters etc.). ...
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How can hashes be unique if they are limited in number? [duplicate]

I'm curious, how can for example SHA-256 be unique if there are only a limited number of them?! For clarification: how many MD5 hashes are there? $16^{32}$ MD5 hashes can be produced. $16^{64}$ SHA-...
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1answer
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How long will brute force of salted SHA-512 hash will take, if salt is known and possible characters in password are known?

Suppose I know that the password is composed of characters [A-Za-z0-9], length is unknown, but maybe less than 8. If I have information about the salt use to perform hashing, and also hashing ...
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4answers
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I think PBKDF2 may be better than Scrypt? Looking for someone to point out my logical error

People seem to mostly recommend scrypt these days, but I'm not sure if this should be the case? I'll structure this post by just making an argument for PBKDF2 over Scrypt and then you can reply ...
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1answer
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HMACSHA256 2.5 times faster than HMACSHA512

According to the answers to a previous question, the 512 version should be faster on x64 devices. And even if it were executed on an x86 (32 bit) device - there shouldn't be such a big difference. ...
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1answer
270 views

Hash function composition - security level

When using two hash functions, g(x)=SHA-512 and f(x)=MD5 g(x) has 512 bit output (using salt) f(x) has 128 bit output. Let's say that z(x)=f(g(x)) meaning the output is 128 bit long. The Question: ...
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What is the probability of a SHA-512 hash containing both digits (0-9) and alphabets (a-f) all the time?

Quite curious to know if ever a SHA-512 hash will contain only digits or only alphabets. Thanks in advance.
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simple encrypt/decrypt [closed]

I would like to encrypt a file by XORing the source message with a prng of my own. The prng is streaming a flow of sha512 hashes. Each hash is produced from the previous hash plus constant string plus ...
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2answers
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Is there an advantage to “weak” hashing and stretching over strong hashing?

Is there any sort of practical advantage to using a stretching algorithm such as PBKDF2 on say SHA256 over a straight SHA512 hash? If the purpose of key stretching is to increase the length and ...
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1answer
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Is there any benefit from using SHA-512 over SHA-256 when AES just truncates it anyway?

I am still not very clear on how AES-256-CBC can use SHA-512 bit keys, but I assume that it just truncates the 512bit hash down to 256bit. In software like GnuPG and OpenPGP, is there any real benefit ...
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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 ...
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1answer
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Would Hashing A Password In Sha512 Using JavaScript Be Secure?

I've created a competition for a few friends of mine that wanted to learn the basics of penetration testing. In said competition, there is one section in which there's a log file you need to check out ...
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how to calculate surge of cpu cycles consumption of an ipsec tunnel with aes256/sha512/dhgroup21?

The project I'm involved with needs to establish around 2500 simultaneous ipsec connections between roadwarriors clients and the ipsec concentrator/gateway. In order to be able to estimate the ...