Questions tagged [md5]

a cryptographic hash function with a 128-bit (16-byte) output, now deprecated

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John the Ripper - Calculating brute force time to crack password

I'm using incremental mode (brute force) mode in John the Ripper to crack Linux MD5 passwords. I'm trying to calculate the time it will take to run through all combinations of 12 passwords (with 12 ...
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39 views

Is there a well-defined algorithm to find preimages of md5?

I know md5 is no longer secure. But is there an algorithm running in polynomial time to find preimages of a given hash, or is it just bruteforce ?
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Disabled MD5 and enabled SHA under SCHANNEL/Hashes in registry. xfreerdp fails with an ssl i/o error

So delving into securing server and not quite understanding how I broke the ability to rdp into my server (using xfreerdp). I disabled MD5 as an available hash and enabled SHA. The exact changes in ...
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1answer
90 views

Is pbkdf2 with hmac using md5 still secure?

I have an old system that can do PBKDF2 with HMAC using MD5, but not SHA-2. Now I know that MD5 is insecure and shouldn't be used for new applications, but https://crypto.stackexchange.com/a/9340/...
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2answers
191 views

Is md5(time . rand) secure enough for a small website?

I'm working on a small game website and don't expect too much traffic. Would md5(time . rand) suffice to have a "random enough" identifier for a game? (Or is it easy to get a clash that way?)...
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1answer
18k views

John the ripper passwd file format with salt not working

I'm trying test password strength in one of our e-commerce sites. I'm using john the ripper to brute-force a password file. The algorithm used by PHP is: $hash = md5($salt . $pass) No other ...
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2answers
463 views

MD5 PPPoE chap crack

My apartment complex uses PPPoE CHAP authentication for internet (Mikrotik router), I want to switch their provided router with my own, however they aren't willing to give me my password. I have ...
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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 ...
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2answers
164 views

Forge certificate for man in the middle attack

I'm trying to analyze a SSLv3 connection. The certificate of the server has a "MD5 with RSA" signature. So I was setting up a local man in the middle attack by setting up a local DNS server ...
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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 ^): ...
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5answers
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Why would one need to encode an MD5 hash string? Is it unsafe to display unencoded?

I was reading this article which talks about a design to shorten URLs, and in the design section, it says that the given URL can be hashed using a hashing algorithm such as MD5, and then be encoded ...
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1answer
612 views

Is it possible to tell if a file's message digest is MD5 or SHA-256?

There's some old data encrypted with OpenSSL 1.0.2, but now OpenSSL is at 1.1.0. I understand from OpenSSL FAQ USER3 that an old file can be decrypted with 1.1.0 by using -md md5. But let's say you ...
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80 views

FedRamp Moderate question about hashing MD5

If I use MD5 but not for cryptography purposes, and not for any authentication or authorization mechanism, Am I in violation of FedRamp Moderate? BR
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8answers
53k views

Why do people still use/recommend MD5 if it has been proven weak since 1996?

It's still a commonly recommended way of hashing passwords, even if its insecurity had been proven in 1996: Therefore we suggest that in the future MD5 should no longer be implemented in applications ...
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4answers
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SHA & MD5 Collisions for shorter strings

This is not for passwords. I understand that MD5 and SHA-512, etc... are insecure because they can have collisions. However, is it still possible to have a collision if the string length is less than ...
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5answers
15k views

Is it secure to use MD5 to verify the integrity of small files (less than 15kb)?

I know that collision for MD5 has been documented since the 90s and that digital certificates based off of MD5 has been demonstrated to be completely compromised back in 2010 but how effective is MD5 ...
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1answer
136 views

Do all files downloaded from the web, come with a checksum to verify the file?

Pretty straightforward question. Take the image here: https://i.imgur.com/oEdf6Rl.png Does it come with a checksum, which I can verify against after I have fully downloaded the file? This question ...
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1answer
2k views

Are there any known MD5 hash collisions of messages of different length?

All the examples of MD5 hash collisions I've come across comprise two different messages (inputs) of the same length. The first and second messages have different values for a number of bits and the ...
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7answers
8k views

How likely is a collision using MD5 compared to SHA256 (for checking file integrity)?

Many sites these days offer MD5 and SHA256 hashes to check the integrity of downloaded files or archives. I wonder how much safer is the use of the SHA256 hashes for integrity checks? Note: Consider ...
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1answer
126 views

Is md5(data + key) secure if a proper hmac function isn't available?

I need to generate a MAC signature for data on a website, but it's in a HTML templating system where there's only a few functions available. The only hashing function available is md5. Ideally, I'd ...
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1answer
174 views

MD5 as X.509 Signature hash algorithm with TLS 1.2 and SChannel

Is it correct that TLS 1.2 prohibits MD5 as a Signature hash algorithm in X.509 certificates used? Is this just an SChannel + TLS 1.2 limitation? Trying to find any webpage/documentation that is ...
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1answer
1k views

Is MD5 hashing possible by divide and conquer algorithm

I would like to compute the MD5 hash of a file The file is uploaded to my webserver by my clients The file is uploaded in pieces (called chunks) The client also sends the md5 hash of the file so that ...
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0answers
61 views

For what good security good principles Facebook using auth digest over ssl?

I want to know if there are no real advantages of using "auth digest" over SSL, then why facebook and many other famous e-commerce websites and SM platforms still uses it. https://...
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1answer
1k views

What is the plaintext password of 'hash part 1' in the shadow file?

on immersivelabs lab Password Hashes II https://dca.immersivelabs.online/labs/password-hashes-ii/ there is a question: What is the plaintext password of 'hash part 1' in the shadow file? shadow.txt ...
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2answers
12k views

Which hashing algorithm shoud I use for a safe file checksum?

For my work I'll need to provide my customer a specific file which will be the result of the work I have done for them. To protect the integrity of the work I have done and to guarantee it has never ...
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4answers
34k views

John the Ripper - Can't get cracked MD5 hash to show

I'm trying to crack some MD5 hashes given in OWASP's BWA on their DVWA site. I was able to use John the Ripper and the very first time it worked fine and it showed the reversed hashes using the code: ...
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3answers
7k views

Is bcrypt(strtolower(hex(md5(pass)))) ok for storing passwords? [duplicate]

I have a large database where passwords are stored as strtolower(hex(md5(pass))) (which is a bad way to store passwords, prone to rainbow tables, cheap to dictionary attack, no salt, etc.), and I'm ...
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2answers
3k views

Migrating password db off MD5 by chaining MD5 and Bcrypt?

I have a legacy system currently storing unsalted MD5 passwords. Unfortunately, some other controls are not in place (like the ability to expire passwords) and I'm trying to upgrade my algorithm to ...
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3answers
3k views

Client side password hashing with static salt - did I find a breach?

I downloaded a software that has a login interface. It's a $100 a month subscription software. I disassembled the software and found that passwords are being sent by combining them with a hard coded &...
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3answers
543 views

Authentication & Authorization via md5(userid + secret + endpoint + payload)?

I am currently developing against a RESTful API that seemingly has a rather weird auth flow. I got an API key consisting of an ID (public) and a "secret" (which seems to be a UUID). Now, ...
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1answer
88 views

If site provides MD5 to check file, can't the comparison string also not be modified? [duplicate]

I am new to this so please bear with me. I was downloading a VM image and I was told to check the MD5. Naturally, I did but wondered, If a hacker would change the file to be downloaded from the ...
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1answer
539 views

How to find just the first character or value of a MD5 hash string

I want to know how to find just the first character or digit in first part of a 64 length string from a MD5 hash. For example, we have a hash: ...
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1answer
460 views

Possible to decode md5 hash of a malicious URL?

Context: I had a virus on my WordPress website server that injected itself into every functions.php file on the server across two different sites. After removing the heavily obfuscated virus code I ...
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2answers
202 views

Hash and data modification

If I have the MD5 and SHA1 hash matches for an encrypted container. Is there no possibility it's been modified? Is it safe to assume the container has never been modified?
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1answer
219 views

Finding original command result from MD5 hash

Basically I hashed the result of the "date" command with md5sum: $date | md5sum The output is indeed in the likes of: e4c94362cd4fd71ec6aca78c7411bdc3 - My question was: is it possible to recover ...
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2answers
562 views

How safe is md5sum in regards to verifying executable files?

is it possible to trick someone into running a malicious executable file instead of a real one provided by a website; assuming they will md5sum the file
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1answer
554 views

Securely displaying hidden integers with MD5

A system I'm studying uses the following mechanism: a 19-digit integer is hashed via the MD5 algorithm and the salt of the integer is shown in plain sight to the user before they take an irreversible ...
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7answers
124k views

Is MD5 considered insecure?

After all these articles circulating online about md5 exploits, I am considering switching to another hash algorithm. As far as I know it's always been the algorithm of choice among numerous DBAs. Is ...
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1answer
978 views

Tools to produce an MD5 collision?

I'd like to learn a bit more about MD5 collisions. So let's assume I have a message m: m = somesecretmessage And I hash that message: z = md5(m) The only know information is z. I do not know m. ...
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1answer
5k views

Can I crack a zip file using Hash Suite on Windows?

I'm trying to crack a password I set on a zip file using Hash Suite but it doesn't seem to work for me (not sure if I'm doing everything correctly). Basically, this is what I've done: Created a ...
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2answers
3k views

How do you manually encrypt text to an md5 hash?

I am aware that you can do something like go to md5online.org or something, but I want to know how to do it manually. For example, you might encrypt it like by taking the length of it and turning the ...
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2answers
490 views

Is it known to what message size are standard hash functions injective?

This simple Python script verifies that all messages of length 1 have different SHA-1 hashes: import hashlib s = set() for i in range(256): s.add(hashlib.sha1(chr(i)).hexdigest()) print len(s) ...
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0answers
446 views

How long will it take to crack a hashed random string

If I generate 128 bit, 512 bit and 1024 bit random strings using either: A native rand() function (C, PHP, Python, etc) OpenSSL random bytes Hardware generated random number And hash the random ...
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2answers
58k views

If hashing is one way, why can we decrypt MD5 hashes?

I have read some times that hashing is a one way function, that is you can make the hash of a message, but you can't recover the original message from the hash, just check its integrity. However, if ...
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3answers
284 views

Disguising the type of hash used

I've read about why MD5, SHA1, and many other hashing functions are insecure, by a lot, but I'm thinking of doing a different approach. It won't increase security, I'm aware of that, but I believe it ...
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4answers
9k views

Is Postgres password-based authentication secure?

According to Postgres's documentation, Postgres's password authentication method uses MD5 hashing to secure the password: The password-based authentication methods are md5 and password. These ...
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2answers
1k views

Is there any recommended approach for "upgrading" MD5 hashes to something secure? [duplicate]

I'm currently dealing with a couple of user accounts containing MD5 hashed passwords. These accounts got migrated from an old system into our current system which uses PBKDF2 for password hashing. I ...
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0answers
71 views

How secure is this combined sha1/md5 hash [duplicate]

Recently we outsourced some work for a website. While reviewing this code I came across the password hash function. I am in no way a security expert besides some basic knowledge (hence outsourcing ...
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0answers
139 views

Attacking a update mechanism using MD5 and RSA

I am currently working on a software challenge where you have to unlock several functions of a piece of software. The software is written in Java. One of them is the update mechanism of the firmware. ...
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6answers
31k views

Reversible Hash Function?

Is there any reversible hash function? The hash function like SHA and MD5 are not reversible. I would like to know if there exist some reversible hash functions?

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