Questions tagged [hash]

A hash algorithm is a function which takes a variable size input and produces a fixed size output. The algorithm tries to make it difficult to predict the output for a given input, find two inputs with the same output, or reconstruct the input from the output.

Filter by
Sorted by
Tagged with
0
votes
0answers
25 views

Help with identifying patterns or cryptographic implement [duplicate]

While I'm pen testing, I came across these values mapping to a store ID. These values are gathered across three different accounts. 0015400000jpjcEAAQ 0015400000jrjH7AAI 0015400000jtDS9AAM It's not a ...
0
votes
0answers
25 views

How does Bitwarden Authenticate and decrypt the vault [closed]

In the Bitwarden Security Whitepaper Page 9-10 (User Login | User Authentication | Access to User Vault Data section), it's written that the master password is encrypted locally and then stored on the ...
0
votes
0answers
11 views

How to change the password hashing scheme in LDAP using an external library with slapd.d config

So I am trying to change the password hashing scheme for LDAP hypothetically let's assume it's pw-argon.so I don't have slapd.conf I have the slapd.d directory where I can make changes dynamically to ...
0
votes
1answer
49 views

Encryption Algorithm With Separate One-Way (Hashing) And Two-Way (Decryption) Keys

In cryptography, generally we have two ways of handling sensitive information. We can use one-way encryption such as hashing. This is useful when we never need to retrieve it again. In this case, we ...
1
vote
2answers
106 views

How many rounds of Bcrypt to use for security equivalent to SHA256?

We regularly use 10000 iterations of SHA256 for hashing passwords. If we want to have similar security, how many rounds/work factor should we use when hashing passwords with bcrypt?
1
vote
0answers
30 views

Encrypting/Salting GPS Coordinates [migrated]

Is there a way to encrypt/salt GPS coordinates irreversibly without the private key/salt, while conserving distance metrics? For example, map 32.16,105.47 to some other values, but be able to ...
1
vote
2answers
77 views

Irreversible encryption - difference to hash?

I keep reading the term "reversibly encrypted" and that confuses me because I thought that is kind of the point of encryption, that it can be decrypted. I googled it, as a good student, and ...
0
votes
0answers
14 views

GRZXW5EDY - Does anyone recognize what kind of hash/id is this? [duplicate]

I am black-box testing a video streaming website. They have 2 kind of IDs for videos. internal_id and external_id. I need to find a way to enumerate internal_id but cannot guess what kind of ID this ...
2
votes
2answers
83 views

CAPTCHA w/o Server-Side Persistence

I would like to implement my own CAPTCHA challenge for a website. The framework I use implements client-side session cookies, which are not encrypted, only signed with server's private key. The ...
1
vote
1answer
83 views

Hashing sessions and retrieving them using cookie(s) with session "id" and "token"

I'm implementing custom authentication & session management system in Node.js & PostgreSQL. My goal is to implement sessions that expire after 2 weeks (if not refreshed/renewed). OWASP and ...
1
vote
0answers
51 views

Choosing the right salt to pseudo-anonymize data and be GDPR compliant

In my company, numeric user IDs are considered PIIs and therefore need to be pseudo-anonymized to be GDPR compliant. To do so, we populate a lookup table where to each ID is assigned a monotonically ...
0
votes
1answer
460 views

John the ripper not able to crack the password

I generated two hashes from this site: Plaintext 1 (p1): world Salt 1 (s1): hello Hash 1 (h1): 936a185caaa266bb9cbe981e9e05cb78cd732b0b3280eb944412bb6f8f8f07af Plaintext 2 (p2): world2 Salt 2 (s2)...
0
votes
1answer
75 views

Does hashing really make this home rolled sso process more secure?

I had configured subdomains on a site to share forms authentication, however decisions were made to change one of websites over to a different domain. So now site A needs to send a user to the site B. ...
0
votes
1answer
57 views

Is there a use for an MDC even when all messages are signed?

I guess I have halfway grasped the concepts of PGP, and I've halfway understood the concept of the Efail attack. However, I still don't understand whether such attacks would be possible (and an MDC ...
0
votes
1answer
91 views

Store a password as an identifier (as safely as possible)... since there is no other choice

I have to deal with a place that has some terrible security practices. For example, this place gives people passwords (eg. domain logon on Windows, but paired with their name as the username) that is ...
2
votes
3answers
163 views

Is it sensible to accept a password + any other random characters for successful authentication?

Supposing a user of my system has set their password to Password123 At the login screen, what would be the security implications of me accepting: Password123 or Password1234 or Password123ABC Based on ...
1
vote
3answers
167 views

To lighten server load, is hashing a client-side Argon2-hashed password with SHA-256 on the server-side at least as safe as server-side only Argon2?

I am trying to achieve better security in my authentication system implementation with both server-side hashing and client-side hashing. (See the first reference below for more prerequisite knowledge.)...
-1
votes
3answers
112 views

Binary versus ASCII representation of a hash - which is more secure

I am using SHA256 to create a hash. Output is captured as a text string (thus "A245B6FF") and that is what has been used to create the digital signature. Since the hash could have been ...
0
votes
1answer
109 views

Secure ajax login form

When the client is logging in, I send an xhr request to the server. However the request looks like this: localhost:80/api/login-ajax/&username=johndoe&password=123456 This is insecure for ...
1
vote
3answers
143 views

Does hashing syslog (or similar) make for good passwords?

I thought of an approach to password generation that I haven't heard of anyone else using. It almost seems too good to be true so I wonder what the downsides are. I'm well aware that you shouldn't &...
7
votes
3answers
190 views

Does there exist any hashing algorithms suitable for comparing data that is similar but not exact matches?

Does there exist any hashing algorithms suitable for comparing data that is similar but not exact matches? For example one where similar input data generates a similar hash, with the difference in the ...
0
votes
1answer
58 views

Is it possible to find out the encryption algorithm used from hexadecimal hash? [duplicate]

Can we find out the encryption method used if we know what is encrypted inside? Let's assume there are around 7-digits 22 or 26 codes (passwords ie just decimals) encrypted to 832 characters ...
0
votes
0answers
75 views

Get encrypted PDF password

For a CTF challenge, I got a locked PDF file with a data folder that contains images, a plaintext file and a wav audio file. I used pdf2john.pl to get the password hash and I performed a brute force ...
1
vote
1answer
124 views

Does using a random number of iterations for PKBDF2-SHA256 help if I only have to protect one key used to encrypt a password protecteded file? [duplicate]

I read about Recommended # of iterations when using PBKDF2-SHA256? I have also read in Why not just use a small but unusual number of hashing rounds? that when there are multiple password to protect, ...
2
votes
1answer
100 views

How to convert passphrase to AES256 key?

My plan is to convert a passphrase in UTF-8 ASCII-US to Unit8Array(32) then use it in: 256bitsKey = Unit8Array(32) from passphase iv = window.crypto.getRandomValues(new Uint8Array(32)); CryptoJS.enc....
9
votes
6answers
3k views

Can iterated hashes be used to create cryptographically secure random data from strong random seed?

I was wondering if generation of sequential hashes from random seed can be considered "random enough" to be used in cryptographic operations? By sequential hashes I mean the following: First ...
7
votes
3answers
4k views

Why not just use a small but unusual number of hashing rounds?

When it comes to hashing passwords, it is nowadays practice to do 100'000 or 200'000 iterations of SHA256/SHA512, or at least something in that ballpark. But my question is, why is it not safe enough ...
0
votes
0answers
11 views

Identify hash pattern inside a string [duplicate]

I believe that this question was answered already, though I couldn't find it. I have several strings that include hash. Each string has hash and some random (or not) add-on. How can I identify the ...
0
votes
0answers
47 views

Using predictable incrementing nonces

I need validation / feedback please with the implementation of a web based client-server application that I am building. I need to make sure that a client's cookies can't be hijacked and therefore I ...
1
vote
1answer
1k views

John the Ripper is unable to crack my SHA1 hashed password

John the Ripper is unable to crack my SHA1 hashed password: john --wordlist=rockyou.txt testing.txt Whenever I do this in Kali Linux, I get this response: Loaded 1 password hash (Raw-SHA1 [SHA1 256/...
0
votes
1answer
52 views

One-way cryptographic algorithm with distinct output and verifiable property

I'm working on a API which is serving content based on user requests. What I'd like to achieve is as follows: Having a constant key stored both on the server and the client machine (as a means of ...
1
vote
2answers
303 views

What is the point of storing hashed passwords? If that file is read, doesn't that mean the computer has already been compromised?

Why is it necessary to store operating system passwords hashed? From what I've learned, passwords are stored on the hard drive/SSD in /etc/shadow. However, if a malicious agent was able to get access ...
0
votes
0answers
64 views

Guessing UUIDv1 hashes?

I'm digging into UUIDv1 generation and bruteforce, in order to take control of a password reset feature of a website which sends a link with a get parameter token=UUIDvX. I'm trying to identify which ...
1
vote
1answer
170 views

How safe is AES 256bitkey encoded in HEX, Base64?

I am using CryptoJS AES 256 encryption: CryptoJS.AES.encrypt(realData, generateKey(passphrase), {iv: iv}); The secret is generated through: function generateKey(passphrase) { const salt = CryptoJS....
0
votes
1answer
65 views

Does john the ripper need to be given the hash format in order to crack it?

Doing some hash rooms on THM and whenever I run the hash files they give me ill just start like this. john --wordlist=rockyou.txt hashfile It will run and then output with a bunch of warnings telling ...
2
votes
1answer
99 views

Security implications of using a non-hash in the password column

Imagine a webapp that uses a traditional email-password-login, with the users-table saving the password salted and hashed using bcrypt. Now a secondary login method should be implemented, like an API ...
0
votes
0answers
13 views

Significant differences in hash cracking speeds? [duplicate]

I'm doing an educational hash research. I generated MD5 hash using online tools and cracked it within a second using Hashcat and certain wordlist (yes, one second). Then I produced a WPA handshake ...
0
votes
1answer
114 views

If a file is digitally signed, is posting a hash very useful for security purposes?

In this question I asked about how to handle situations when SHA-256 hashes are not available for a file downloaded from the internet that contains executable code. Another community member ...
0
votes
1answer
60 views

Making already hashed wordlists of all possible combinations [duplicate]

Let us imagine a situation where a company stores its user passwords (let's ignore salts, etc for now) using some hash (say sha256) and the company gets breached. All of the username and password ...
1
vote
0answers
61 views

When file hash not available, how to best check authenticity of a file?

Normally, The Document Foundation (TDF) publishes the SHA-256 and SHA-1 hashes, along with the MD5 checksum, for all LibreOffice releases. For example, see this. However, for their current release (...
2
votes
0answers
53 views

Pros and Cons of hashing password on DB or on API server interacting with db [closed]

I'm trying to understand what is good/bad about hashing a password on a database (like postgres) as opposed to hashing it on an api server and then sending it hashed to the db. Can anyone speak on ...
0
votes
2answers
164 views

How likely is a SHA256 hash to be brute forced on this conditions?

If a string has a length of 16 characters, but it is also known that the first 2 characters are fixed, and that the rest of the string has random letters but letters only, no digits nor special chars, ...
10
votes
4answers
2k views

Password management of emailed cleartext passwords

If a website emails a password in cleartext when you use the "forgot password" function, is there any possibility that the password is hashed? It does generate a different password if you ...
0
votes
2answers
97 views

Could blockchain be useful for a protocol to verify content from a trusted publisher in the way I'm thinking of? [closed]

The problem with static software whitelisting is that in the real world, employees with versatile jobs need to run unexpected programs. Company sets up a whitelist to limit what programs can run - ...
26
votes
3answers
7k views

Known strings to have the same MD5 hash, not colliding in real life?

I was reading this article about MD5 hash collisions in which it clearly states that these two strings (differences marked with ^): ...
22
votes
4answers
8k views

Does password length / complexity make any difference if hashes are leaked?

Password length/complexity only mitigates a brute force attack, correct? In the event of a hash leak, since any algorithm is a fixed length, there could potentially be a pre-image* with a very short / ...
1
vote
0answers
140 views

Using John the Ripper for Blockchain.info second password

Is there a way to use JtR for Blockchain.info's (v2) secondary password? I already tried the blockchain2john.py file, and it does not ask for primary password (which I know already) so it is going to ...
-3
votes
2answers
131 views

Number of biometric samples required to form an exhaustive set of fingerprint hashes?

Number of biometric samples required to form an exhaustive set of fingerprint hashes? Slight variations in the sample produce different hash values of the sample data. The answer linked below ...
0
votes
2answers
155 views

Odds of two messages sharing the same hash prefix

If only the first h bits of a certain SHA256 hash H of a certain message M are known, and one had managed to successfully guess an input message M' whereby SHA256( M' ) yielded an H' whose first h ...
0
votes
2answers
72 views

Does using subkeys provide better protection in this instance?

I was thinking of implementing the following scheme for encryption of many independent files: From the password, which is given by the user, generate a master key using for example HMAC-SHA. From ...

1
2 3 4 5
43