RNDr. Vlastimil Klíma (born February 19, 1957) is a Czech cryptologist and computer security

Computer security

Computer security is a branch of computer technology known as information security as applied to computers and networks. The objective of computer security includes protection of information and property from theft, corruption, or natural disaster, while allowing the information and property to...

 expert. He is an author of several works in the field of cryptographic hash function

Cryptographic hash function

A cryptographic hash function is a deterministic procedure that takes an arbitrary block of data and returns a fixed-size bit string, the hash value, such that an accidental or intentional change to the data will change the hash value...

s and digital signature

Digital signature

A digital signature or digital signature scheme is a mathematical scheme for demonstrating the authenticity of a digital message or document. A valid digital signature gives a recipient reason to believe that the message was created by a known sender, and that it was not altered in transit...

s. After he published one of the most efficient algorithm

Algorithm

In mathematics and computer science, an algorithm is an effective method expressed as a finite list of well-defined instructions for calculating a function. Algorithms are used for calculation, data processing, and automated reasoning...

s for finding hash collision

Hash collision

Not to be confused with wireless packet collision.In computer science, a collision or clash is a situation that occurs when two distinct pieces of data have the same hash value, checksum, fingerprint, or cryptographic digest....

s in the MD5

MD5

The MD5 Message-Digest Algorithm is a widely used cryptographic hash function that produces a 128-bit hash value. Specified in RFC 1321, MD5 has been employed in a wide variety of security applications, and is also commonly used to check data integrity...

 function, he designed his own concept of a hash function, which entered the NIST hash function competition

NIST hash function competition

The NIST hash function competition is an open competition held by the US National Institute of Standards and Technology for a new SHA-3 function to replace the older SHA-1 and SHA-2, which was formally announced in the Federal Register on November 2, 2007...

 under the name Blue Midnight Wish.