25.01.2026, 20:58
The most famous and commonly used "big" number for a Caesar cipher is
13 (often referred to as ROT13).
Here is a breakdown of key numbers associated with the Caesar Cipher:
13 (ROT13): This is the most common variant because it is self-decoding. Shifting the alphabet by 13 places twice brings you back to the original text (13 + 13 = 26).
3: Historically, Julius Caesar himself is reported to have used a shift of 3.
1–25: The Caesar cipher is a "shift cipher" that can use any integer shift from 1 to 25, as there are only 25 possible functional shifts in the 26-letter English alphabet.
26 (Base): While not a shift amount, 26 is the modulo base, meaning a shift of 26 is the same as a shift of 0 (no change), and a shift of 27 is the same as a shift of 1.
For maximum obfuscation while remaining a "Caesar Style" cipher, 13 is the standard, popular choice
13 (often referred to as ROT13).
Here is a breakdown of key numbers associated with the Caesar Cipher:
13 (ROT13): This is the most common variant because it is self-decoding. Shifting the alphabet by 13 places twice brings you back to the original text (13 + 13 = 26).
3: Historically, Julius Caesar himself is reported to have used a shift of 3.
1–25: The Caesar cipher is a "shift cipher" that can use any integer shift from 1 to 25, as there are only 25 possible functional shifts in the 26-letter English alphabet.
26 (Base): While not a shift amount, 26 is the modulo base, meaning a shift of 26 is the same as a shift of 0 (no change), and a shift of 27 is the same as a shift of 1.
For maximum obfuscation while remaining a "Caesar Style" cipher, 13 is the standard, popular choice