Cryptology is the technique of encryptingmessages. It has a historical background and knows the most different techniques and procedures to make messages unrecognizable. Only authorized persons are able to read the encrypted messages, because they know the algorithms and the key with which the encrypted messages can be decrypted.
As far as encryption methods are concerned, besides trivial writing methods, there are mechanical encryption machines that were used in times of war. The classical encryption also knows transmission methods in which the messages are not encrypted, but hidden in another message. This technique is called steganography.
Cryptology uses complex mathematical formulas and algorithms, which are constructed in such a way that they cannot be reproduced if possible. To ensure that the algorithms and equations used cannot be solved by third parties, they work with prime numbers, discrete logarithms and elliptic curves. Cipher keys are calculated and transmitted to authorized persons for decryption.
The many modern encryption techniques include many different algorithms and various ciphers such as the block cipher, stream cipher, substitution cipher and transposition cipher. But also public and private key methods, digital signatures and digital certificates.