Tool to decrypt/encrypt with rot13. ROT-13 cipher is a particular case of the Caesar cipher, where the shift is equal to 13, this allow the cipher to be reciprocal.

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Tool to decrypt/encrypt with rot13. ROT-13 cipher is a particular case of the Caesar cipher, where the shift is equal to 13, this allow the cipher to be reciprocal.

Rot-13 decryption is identical to encryption, due to the reciprocal substituting alphabet used:

NOPQRSTUVWXYZ

ABCDEFGHIJKLM

Example: QPBQR becomes DCODE.

Rot-13 has the same function for encryption and decryption, it is said to be involutive

How to recognize ROT-13 ciphertext?

Frequency analysis shows a shift of 13 letters (The E is replaced by an R, which should be the most present letter).

A message encoded by Rot13 has an index of coincidence similar to the language of the plain text.

What are the variants of the Rot-13 cipher?

Rot-13 is in fact a Caesar cipher with a shift of 13. As this code only works with letters, it was proposed to use it with the Rot5 for numbers or the Rot47 for ASCII values.

What is the particularity of ROT13 Cipher?

An offset of 13 allows the encryption to be reversible. The encryption and decryption method are identical. Applying 2 consecutive encryptions (2 shifts of 13) heads to find the original text.

Source code

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