Skip to main content

Hash function

What is a hash function?

A hash function is a mapping that breaks down a larger input set into smaller target sets, which in turn reference the original input set. Using hashing, the individual elements from the input set are first mapped to a key and then to the corresponding hash values, which represent the original data in a specific way.

The input set can consist of different data and formats, such as:

  • Strings
  • Lists
  • Files

General information

Hash functions are used in various areas to facilitate work with large amounts of data or to implement secure digital communication.

The hash procedure is used in the following areas, among others:

  • when storing gigantic amounts of data in databases
  • checksums, which are used to check data integrity
  • in programming to create complex data structures

By loading the video, you agree to YouTube’s privacy policy.
Learn more

Load video

Significance for programming

Hash functions are not only used in various areas of information technology, but hashing algorithms are also used in programming to increase security and realize complex data structures. In principle, however, the degree of security is relative, because crackers and hackers try to uncover security holes in existing algorithms, while security researchers are continuously working on new hash functions.


The choice of a suitable hash function depends primarily on the available computing power.

For simple application scenarios such as data structures or databases, hashing algorithms can also be used whose hash values are significantly less secure than cryptological hash methods.

Further links

Do you have any more questions?

Please contact us

Further contents