An encryption algorithm is required in order to transmit confidential information over insecure information channels, for example, over a network. The information is encrypted by the originator prior to transmission and decrypted by the recipient following transmission.
A symmetric encryption algorithm is one in which the originator's and recipient's keys are identical. Encryption algorithms in which the originator and recipient have different keys are called asymmetric.
A summary of all the encryption algorithms available in CrypTool is contained on the help page for the Crypt/Decrypt menu.
Further information on encryption algorithms will be found in the script on Encryption Algorithms.