ROT13暗号

ROT13またはカスタムシーザー暗号回転を使用してテキストをエンコード・デコードします。ROT13は自己反転 - 2回適用すると元に戻ります。

Shift Amount (1-25)

Cipher Mapping

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

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

Input Text

Shift +13 (Encode)

Shift -13 (Decode)

About Caesar Cipher:

• ROT13: Shift by 13, self-reversing (encode = decode)
• Each letter is replaced by one that is N positions down the alphabet
• Non-alphabetic characters (numbers, symbols, spaces) are preserved
• Named after Julius Caesar who used it for secret correspondence
• Not secure for actual encryption - only for obfuscation/fun

ROT13 - 技術的な詳細

ROT13 shifts each letter by 13 positions in the alphabet. Since there are 26 letters, applying ROT13 twice returns the original text. It was commonly used to hide spoilers in forums.

コマンドラインでの代替方法

# Using tr command
echo 'Hello World' | tr 'A-Za-z' 'N-ZA-Mn-za-m'

# Using Python
python3 -c "import codecs; print(codecs.encode('Hello', 'rot_13'))"