🔐 替换密码

尤利乌斯·凯撒使用的最著名的古典密码。通过我们的交互式编码器，将字母表中的每个字母移动固定的位置，并配有密码轮可视化功能。

• 可调节的移位值 (1-25)
• 交互式凯撒密码轮可视化
• 提供所有25种解法的暴力破解器
• ROT1, ROT3, ROT13 快速预设
• 保留大小写并处理数字

Ancient Hebrew cipher that reverses the alphabet (A↔Z, B↔Y, C↔X). Simple yet elegant monoalphabetic substitution with self-reversible properties for easy encoding and decoding.

• Self-reversible encryption/decryption
• Works with any alphabet system
• Biblical cryptography examples
• Instant bidirectional conversion
• Historical context and usage

Special case of Caesar cipher with 13-letter shift. Widely used in online forums for hiding spoilers and puzzle solutions. Apply ROT13 twice to recover original text.

• Self-inverse encryption (ROT13 = decrypt)
• Popular in UNIX systems and forums
• Hide spoilers and puzzle solutions
• One-click encode/decode toggle
• Internet culture and usage examples

Advanced cipher using linear algebra and modular arithmetic. Each letter is encrypted using the formula E(x) = (ax + b) mod 26, providing stronger security than simple shift ciphers.

• Two-key mathematical encryption (a, b)
• Modular arithmetic calculator
• Multiplicative inverse finder
• Valid key combination checker
• Step-by-step encryption process

The "unbreakable cipher" using a keyword to apply multiple Caesar shifts. More secure than monoalphabetic substitution, resisting simple frequency analysis attacks.

• Keyword-based polyalphabetic encryption
• Interactive Vigenère square/table
• Kasiski examination for cryptanalysis
• Index of coincidence calculator
• Keyword strength analyzer

Historic digraph cipher used in World War I. Encrypts pairs of letters using a 5×5 key square, providing significantly better security than single-letter substitution.

• 5×5 Polybius square generator
• Digraph pair encryption rules
• Custom keyword support
• Visual key square display
• Military cryptography history