MD5 encryption method
MD5 is one of a series of message digest algorithms designed by Professor Ronald Rivest of MIT (Rivest, 1994). When analytic work indicated that MD5's predecessor MD4 is to be insecure, MD5 was designed in 1991 as the successor of MD4 (MD4 weaknesses found by Hans Dobbertin). In cryptography, MD5 (Message-Digest algortihm 5) is a cryptographic hash function is used extensively with 128-bit hash value.
On the Internet standard (RFC 1321), MD5 has been utilized in a variety of security applications, and MD5 are also commonly used for testing the integrity of a file.
SHA is a set of cryptographic hash functions designed by the National Security Agency (NSA) and published by NIST as a U.S. Federal Information Processing Standard.
SHA is the Secure Hash Algorithm. The types of the SHA SHA-0, SHA-1, and SHA-2.
For SHA-2 algorithms are identical to the summary measure of well-known variables as SHA-224, SHA-256, SHA-384, and SHA-512.
Peter Selinger has made a demonstration of two different pieces of executable files but have the same MD5 hash value. The scenario is of two files one is the original file, another is a bad file. Both have the size and the same MD5 hash value.
This will trick the similarity hash Tripwire and the people who download files from the internet. Tripwire will silence even though the file has been modified executables attacker. So wheb the man who download an executable file from the internet
it turns out that he had received file has been changed mid-way.
However, because after the calculated value hash matches with the original file, the victim will think that's true and original file but different.
Why SHA512 is a superior hashing algorithm to MD5.
It depends on your use case. But there are areas where MD5 has been broken:
1. For starters: MD5 is old, and common. There are tons of rainbow tables against it, and they're easy to find. So if you're hashing passwords (without a salt - shame on you!) - using md5 - you might as well not be hashing them, they're so easy to find. Even if you're hashing with simple salts really.
2. Second off, MD5 is no longer secure as a cryptographic hash function (indeed it is not even considered a cryptographic hash function anymore as the Forked One points out). You can generate different messages that hash to the same value. So if you've got a SSL Certificate with a MD5 hash on it, I can generate a duplicate Certificate that says what I want, that produces the same hash. This is generally what people mean when they say MD5 is 'broken' - things like this.
3. Thirdly, similar to messages, you can also generate different files that hash to the same value so using MD5 as a file checksum is 'broken'.
Algorithm SHA-512 hash functions including the type of which is the development of the algorithm SHA-1. hash function
map the message regardless of length M with a hash value of fixed length h (particular, depending
the algorithm). For the algorithm SHA-512 hash value of the resulting length is 512 bits. Hash function that
produces output with its small size vulnerable to attact birthday [4]. This attack was carried out with
how to get two random messages that have the same hash value h.
SHA-512 as the hash function has properties as follows:
(1). h is easily calculated when given M.This trait is a must, because if h is difficult calculated, then the hash function can not be used.
(2). M can not be counted if it is only known to h.This trait is also called one-way function, or easy to calculate h and difficult to be returned to the M
original. These properties are important in cryptographic techniques, as if without this trait then the attacker can find the value of M by knowing its hash value h.
(3). It is impossible sought M and M 'such that H (M) = H (M').This trait is also called collision free. These properties prevent the possibility of forgery.
