Caesar cipher

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This simple cipher is also known as shift cipher, A=C, A=N or ROT13. It is very easy to work with but can be cracked just as simple. If is expecially famous for having been used by roman emperor Caesar. Nowadays the cipher is mainly used to obscure messages so they cannot be read unintentionally. In the internet ROT13 is often used to mark texts that some people probably don't want to read. Of course it is also used in school classes to transmit hidden messages and at scouting and other youth organisations.

The letters of the text are shifted "along the alphabet". When you shift just one position, an A becomes a B, a B becomes a C, and so forth. Of course you can also shift further. The original caesar cipher shifts for two positions (so that A=C). Also popular is to shift for 13 positions (or half the alphabet), A=N. This is quite convenient since to create a cipher table you only need to write each letter once and still can use this table for encryption and decryption:

A B C D E F G H I J K L M
N O P Q R S T U V W X Y Z

To encrypt or decrypt a message, you only need to exchange the letter in the source text with the letter just above or below in the cipher table. The word "HELLO" thus gets "URYYB".

Here you can encrypt and decrypt your texts. Special characters and digits are not changed.