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

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55
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3answers
19k views

How can I create a password that says “SALT ME!” when hashed?

How can I create a password, which when directly hashed (without any salt) with md5 will return a string containing the 8 characters "SALT ME!". The hope is that a naive developer browsing through his ...
28
votes
3answers
55k views

Is SHA1 better than md5 only because it generates a hash of 160 bits?

It is well known that SHA1 is recommended more than md5 for hashing since md5 is practically broken as lot of collisions have been found. With the birthday attack, it is possible to get a collision ...
26
votes
3answers
3k views

MD5 collision attacks: are they relevant in password hashing?

DISCLAIMER: This is not an endorsement of MD5 as a password hashing function. I know about parallelization, GPUs, and dedicated password hashing functions like bcrypt and scrypt. With that out of ...
17
votes
8answers
13k views

Why do people still use/recommend MD5 if it is cracked since 1996?

It's still commonly recommended way of hashing passwords, even if it's insecurity had been proven in 1996 Therefore we suggest that in the future MD5 should no longer be implemented in ...
14
votes
2answers
493 views

Password Salts and Randomness

Alright, so I understand that users are the kind of beasts who like to use one password and make it short and easy to remember (like "doggies"). If I understand correctly, that's one reason we use ...
12
votes
7answers
2k views

Why does some popular software still use md5?

Nowadays no one dares to defend md5 for any use, and of course they should not! However, much popular software still uses md5 in applications such as password hashing (although it's not simple/plain ...
11
votes
6answers
8k 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 ...
7
votes
1answer
682 views

Does bcrypt on top of md5 reduce its security?

A GitHub project I recently checked has a flawed security as they're using an unsalted md5() to hash the passwords. I opened a bug and they acknowledged it. However, the transition from md5() to ...
7
votes
3answers
565 views

Is Using MD5 Sufficient Reason to Reject This Payment Processor?

I'm evaluating a credit card processor[1], and I noticed they are using MD5 as part of a salted hash algorithm to protect a secret key. Since I know MD5 is generally considered broken, this feels like ...
7
votes
1answer
773 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 ...
7
votes
2answers
710 views

Does the md5 (or any hash for that matter) of a string include the null terminator?

Does the md5 (or any hash for that matter) of a string include the null terminator in its calculations? That is does the hash of a string equal the hash of the sequence of bytes that represents the ...
6
votes
3answers
624 views

Are online hash calculators dangerous?

I was about to use an online MD5 checksum calculator when I realized that my result could be added to a database. This is significant because the string I was going to type in was my bank password. ...
6
votes
3answers
2k views

How exactly is MD5 vulnerable to collission attacks?

I've often read that MD5 (among other hashing algorithms) is vulnerable to collisions attacks. I understand the collision part: there exist two (or more) inputs such that MD5 will generate the same ...
6
votes
2answers
1k views

Truncating the output of SHA256 to 128 bits

suppose we need/prefer 128 bit hash output. for example to generate a 128 bit encryption key or, in other applications (e.g. file integrity verifications), to consume less storage space. i don't know ...
6
votes
3answers
725 views

NTLMv2 resistance to bruteforcing

I have a question regarding NTLMv2 resistance to password bruteforcing. I know that some modern graphic processors (like Radeon 6990) are able to calculate billions hashes per second and crack NTLM ...
5
votes
2answers
1k views

Do Client Nonces enhance the security of HTTP Digest Auth?

As far as I understand the answer at http://security.stackexchange.com/a/3024/13447, client nonces are meant to prevent attackers from amortizing the costs of brute-force hash computations by being ...
4
votes
2answers
2k views

Why do most hashing functions produce hashes that have characters a-f 0-9?

This is something I never understood about hashing functions. I know that algorithms like whirlpool and blowfish both produce outputs that don't follow this pattern, but why is it that most do? Is ...
4
votes
2answers
1k 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 ...
4
votes
3answers
2k views

Using MD5 for file integrity checks?

General Always check the MD5 hashes of the .NET Framework assemblies to prevent the possibility of rootkits in the framework. Altered assemblies are possible and simple to produce. Checking ...
4
votes
4answers
1k views

Why does MD5 hash starts from $1$ and SHA-512 from $6$? Isn't it weakness in itself? [duplicate]

I have moved this question from stackoverflow to this place. I know it may be a question about 'opinion' but I am not looking for a private opinion but a source of the final decision to keep it this ...
4
votes
2answers
677 views

Is HTTP Digest + MD5 still an alternative to consume my own api?

I'm reading a lot about implementing security constraints to a REST API. There are a lot of methods, some better than others for 3party applications or to consume my own API. HTTP Basic + TLS (with ...
4
votes
1answer
913 views

Code signing with MD5 on Windows 8

I discovered that a signed installer package that is reported as correctly signed on Windows 7 and earlier, is reported as "corrupt" in IE10 on Windows 8. Further investigation showed that the ...
4
votes
1answer
94 views

MD5 security concerns in download verification

The MD5 hashing algorithm is known to be vulnerable to collisions for a number of years now, see its Wikipedia entry. Still, I see that in many places throughout the web, MD5 is used to verify ...
3
votes
2answers
2k views

How weak is MD5 as a password hashing function ?

A professor told us today, that MD5 is weak. I understand his chain of thought but pointed out, that IMHO MD5 is a good way to go if you would use a long (even really long) dynamic salts and static ...
3
votes
2answers
894 views

Program binaries or files with same MD5 hash

I'm looking for 2 different program binaries or 2 different files with the same MD5 hash to prove its weakness and the collisions in the algorithm.
3
votes
3answers
409 views

Client-side hashing of password before sending it from login form [duplicate]

I have just realized, that my web application is sending unencrypted passwords from login form. It's just like that -- I've analysed, that string sent by user from login form is hashed with MD5 (which ...
3
votes
2answers
362 views

Distributed md5 crack software?

I'm studying about cracking password using brute force, and in my way I found softwares like John the Ripper and MDCrack, that works really nice, but are restricted to one machine. There is some ...
3
votes
1answer
374 views

MD4 or MD5 speed depends on data or just on data size?

Im just wondering ... Lets say, I want to compute an MD5 hash from a given buffer which is an empty (memset(buffer, ' ', sizeof(buffer));) buffer with size of 512. I also want to compute MD5 hash on ...
3
votes
1answer
709 views

Replacing weak SSH fingerprint algorithms

Even though MD5 has been broken for years and its vulnerabilities have been used to create real-world rogue X.509 CAs and other horrible things, OpenSSH and PuTTY still use MD5 as the default public ...
3
votes
2answers
169 views

How safe is to secure sensitive content by URL with MD5 hash and no other authorization?

Suppose we have website that use MD5 hash in URL like this: http://somewebsite.com/XXX/ where XXX is MD5 hash. Content of this website may have sensitive information like transaction details with ...
3
votes
2answers
523 views

Does PCI ban using MD5 to store sensitive data?

Just had a vendor tell me that because their PCI auditors did not recommend banning the use of unsalted MD5 to store sensitive data at this time with with their current level of PCI compliance that ...
3
votes
3answers
610 views

Why are MD5 collisions dangerous?

I understand that the MD5 algorithm isn't collision resistant, and that collisions between data of arbitrary size can be found with more efficient methods than brute-forcing. However, I have read ...
3
votes
1answer
725 views

How does VTP authentication prevent unauthorized access (Can the password be cracked given captured packets)

I know that when setting up VTP across switches in a network you should set a secret/password to prevent unauthorized requests. My question is I know that this uses an MD5 hash to ensure that ...
3
votes
1answer
348 views

Cracking DES(Unix)/MD5 ARP

This is a basic exemple of Unix Pass Encryption. I have little Hash of MD5 ARP : user50:$apr1$w7YNTrjQ$0/71H7ze5o9/jCnKLt0mj0 user60:$apr1$AIw2h09/$Ti0TRlU9mDpCGm5zg.ZDP. I need to find the pass ...
2
votes
1answer
247 views

Unknown encryption string [closed]

I'm trying to learn about encryption and decryption methods when I faced this string: {MD5}JfnnlDI7RTiF9RgfG2JNCw== MD5 is 16-byte string, so anyone know what type of encryption is this and why ...
2
votes
1answer
155 views

How fast can a MD5 collision be found

If I have a salt of 16bytes and 16bytes of data, how fast can one find another 16bytes of data so that MD5(salt + data) == MD5(salt + other data)? I don't expect an answer accurate to the nanosecond, ...
2
votes
4answers
546 views

Is hashing the hash considered an extra level of security [duplicate]

As in md5(md5(md5(x)))... I can remember coming across that in some piece of code. If the attacker can somehow reverse md5(md5(md5(x))) into md5(md5(x)) then he certainly can reverse md5(md5(x)) into ...
2
votes
2answers
1k views

What exactly is 'single' mode in John the Ripper doing?

I'm testing out John the Ripper (1.7.9 Jumbo 7) on a file containing MD5 hashes without any usernames. I've been experimenting with different rules and configurations – I am currently using a wordlist ...
2
votes
2answers
72 views

How secure is a MD5 hash of an 128bit key

Apparently, for the Android KeyChain an encrypted master key is stored along the MD5 hash of the unencrypted Key. How secure is that? MD5 is known to have collisions, but I guess we can assume with an ...
2
votes
3answers
992 views

Preventing dictionary attacks against hashed passwords [duplicate]

Possible Duplicate: How to securely hash passwords? I have a website and on that website I use SHA-256 and salt my user's passwords. What I'm doing right now is padding each letter of the ...
2
votes
2answers
187 views

injected code decode

Recently I saw a domain of mine was hacked and the hacker have injected his code in some encryption format as below. <?php $l___l_='base'.(32*2).'_de'.'code';$l___l_=$l___l_(str_replace("\n", '', ...
2
votes
2answers
1k views

Is there an index of all md5 collisions?

I am about to build a caching system based on md5 to generate file names out of lists of natural numbers. The inputs would be groups like: 1,18,94,100,266,1854. I know there are some collisions in ...
1
vote
4answers
1k views

Shall I need to use MD5 algorithm in both JavaScript and PHP for login authentication?

I have a login form with username and password. I post this form data to a PHP file. For security reasons I want to encrypt my password in the database and network. Now I have done now following ...
1
vote
4answers
2k views

Antivirus Engine based MD5 or SHA1 hash?

I'm trying to understand more about MD5 and SHA1 hashes algorithms and their behavior in serious security software(found this but not helped me more). Why does ClamAV use additional scanning ...
1
vote
2answers
143 views

Ip4v Rainbow Table [closed]

a friend challenged me to find out the ip from the new web server he uses. Is there a rainbow table or something similar with all possible adresses or are 4 billion numbers to much for a normal ...
1
vote
3answers
1k views

Email activation string with MD5'd random number and email secure?

For the registration on my PHP powered website, I require email confirmation. After a user registers, a string is generated with the following code and sent to their email address. $key = ...
1
vote
2answers
128 views

Difference between OS X md5 and gnu md5sum

I have installed the "md5sum" utility on my Mac and there was also a "md5" binary pre-installed in /sbin. My problem and question is this: "Isn't MD5 a standard algorithm?" Because I get different ...
1
vote
1answer
60 views

Multi hash security [duplicate]

Is md5(sha1(pass)) more secure than md5(pass)? For example in case of sqli when attacker cant get our hashing schema, brute force or dictionary attack would be much less efficient. Am i right or is it ...
1
vote
2answers
293 views

Which hashing algorithm is ideal for use on the web? [duplicate]

I am new here, and have poked around the site looking for an overview of which hash algorithm to use on the web and why. It seems to be the consensus that SHA-256 or other SHA-2 family algorithms are ...
1
vote
1answer
327 views

The brute-force resistence of bcrypt versus MD5 for password hashing?

Can anyone give me an idea? Assume the salt(s) is/are known. For example, if I have a $k$-character long password that is hashed in MD5 versus bcrypt, is there a way to estimate how much more time it ...