In cryptography, MD5 (Message-Digest algorithm 5) is a widely used cryptographic hash function with a 128-bit hash value. As an Internetstandard (RFC 1321), MD5 has been employed in a wide variety of security applications, and is also commonly used to check the integrity offiles. However, it has been shown that MD5 is not collision resistant[1]; as such, MD5 is not suitable for applications like SSL certificates or digital signatures that rely on this property. An MD5 hash is typically expressed as a 32 digit hexadecimal number.
MD5 was designed by Ron Rivest in 1991 to replace an earlier hash function, MD4. In 1996, a flaw was found with the design of MD5. While it was not a clearly fatal weakness, cryptographers began recommending the use of other algorithms, such as SHA-1 (which has since been found vulnerable). In 2004, more serious flaws were discovered, making further use of the algorithm for security purposes questionable.In2007 a group of researchers including Arjen Lenstra described how to create a pair of files that share the same MD5 checksum.In an attack on MD5 published in December 2008, a group of researchers used this technique to fake SSL certificate validity.
The SHA hash functions are a set of cryptographic hash functions designed by the National Security Agency (NSA) and published by the NIST as a U.S. Federal Information Processing Standard. SHA stands for Secure Hash Algorithm. The three SHA algorithms are structured differently and are distinguished as SHA-0, SHA-1, and SHA-2. The SHA-2 family uses an identical algorithm with a variable digest size which is distinguished as SHA-224, SHA-256, SHA-384, and SHA-512.
SHA-1 is the best established of the existing SHA hash functions, and is employed in several widely used security applications and protocols. In 2005, security flaws were identified in SHA-1, namely that a possible mathematical weakness might exist, indicating that a stronger hash function would be desirable.Although no attacks have yet been reported on the SHA-2 variants, they are algorithmically similar to SHA-1 and so efforts are underway to develop improved alternatives. A new hash standard, SHA-3, is currently under development — the function will be selected via an open competition running between 2008 and 2012.
In the table below, internal state means the “internal hash sum” after each compression of a data block; see Merkle-Damgård construction for more details.
| Algorithm and variant |
Output size (bits) | Internal state size (bits) | Block size (bits) | Max message size (bits) | Word size (bits) | Rounds | Collisions found | |
|---|---|---|---|---|---|---|---|---|
| SHA-0 | 160 | 160 | 500 | 264 ? 1 | 32 | 80 | Yes | |
| SHA-1 | 160 | 160 | 512 | 264 ? 1 | 32 | 80 | None (263 attack) | |
| SHA-2 | SHA-256/224 | 256/224 | 256 | 512 | 264 ? 1 | 32 | 64 | None |
| SHA-512/384 | 512/384 | 512 | 1024 | 2128 ? 1 | 64 | 80 | None | |
First of all, you page has some errors in part of its php script, in the iframe.
Also, be careful using plain MD5 to store your client’s data. Sites like netmd5crack can reverse simple MD5 hashes via a reverse lookup. The moral of they story: Salt your hashes!
Thanks Brian for the alert/comment,there was a recent server change for my blog and the php script wasn’t compatible with the version in my new server which resulted in undefined function error.
At present I do not store hashes produced on my pages.It just serve has an Online hash generator of all popular algorithm at one place.
Its true to salt your hashes for security but netmd5crack can only reverse lookup for prehashed string in the database/rainbow table.They also store the “string” hashed on their pages and store them in their database and use them in MD5 Cracker.
eee, respect! cool post!
Thank you, I regularly read your blog, I have some questions for you, let me know if you want to contact me by e-mail
Hi guys,
here’s a powerful md5 decrypter
Pretty cool!
David