MD5 is the most commonly used algorithm to store the passwords. This is a one-way encryption algorithm, so you will not be able to decrypt and get the original data.
MD5 (Message-Digest algorithm 5) is a widely-used cryptographic hash function with a 128-bit hash value. MD5 was designed by Ronald Rivest in 1991 to replace an earlier hash function, MD4. As an Internet standard, MD5 has been employed in a wide variety of security applications, and is also commonly used to check the integrity of files.
Today I visited a website which is having a large database of MD5 Hash and the corresponding values, which will make the MD5 decryption possible for at least many words.
the first hash I entered is decrypted well, but the second hash which is a hash of the first hash could not be decrypted. So it will be better to use the MD5 encryption done twice or more times for better security.
Do you want to try it a MD5 Decrypter ? check this website where they claims they have more than 40 billion decrypted MD5 hashes.