ROT13

ROT13 is a simple letter substitution cipher that replaces a letter with the 13th letter after it in the Latin alphabet. It is a special case of the Caesar cipher which was developed in ancient Rome, and used by Julius Caesar in the 1st century BC (see timeline of cryptography).

ROT13 may be referred to as Rotate13, ROT-13, rotate by 13 places, or sometimes by its autonymEBG13.