# Cryptography - [Introduction](https://www.ctfrecipes.com/cryptography/reconnaissance.md) - [General knowledge](https://www.ctfrecipes.com/cryptography/general-knowledge.md) - [Encoding](https://www.ctfrecipes.com/cryptography/general-knowledge/encoding.md): Data standard - [Character encoding](https://www.ctfrecipes.com/cryptography/general-knowledge/encoding/character-encoding.md) - [ASCII](https://www.ctfrecipes.com/cryptography/general-knowledge/encoding/character-encoding/ascii.md) - [Unicode](https://www.ctfrecipes.com/cryptography/general-knowledge/encoding/character-encoding/unicode.md) - [UTF-8](https://www.ctfrecipes.com/cryptography/general-knowledge/encoding/character-encoding/utf-8.md) - [Data encoding](https://www.ctfrecipes.com/cryptography/general-knowledge/encoding/data-encoding.md) - [Base16](https://www.ctfrecipes.com/cryptography/general-knowledge/encoding/data-encoding/base16.md): Hexadecimal encoding - [Base32](https://www.ctfrecipes.com/cryptography/general-knowledge/encoding/data-encoding/base32.md) - [Base64](https://www.ctfrecipes.com/cryptography/general-knowledge/encoding/data-encoding/base64.md) - [Maths](https://www.ctfrecipes.com/cryptography/general-knowledge/maths.md) - [Modular arithmetic](https://www.ctfrecipes.com/cryptography/general-knowledge/maths/modular-arithmetic.md) - [Greatest Common Divisor](https://www.ctfrecipes.com/cryptography/general-knowledge/maths/modular-arithmetic/greatest-common-divisor.md) - [Fermat's little theorem](https://www.ctfrecipes.com/cryptography/general-knowledge/maths/modular-arithmetic/fermats-little-theorem.md) - [Quadratic residues](https://www.ctfrecipes.com/cryptography/general-knowledge/maths/modular-arithmetic/quadratic-residues.md) - [Tonelli-Shanks](https://www.ctfrecipes.com/cryptography/general-knowledge/maths/modular-arithmetic/tonelli-shanks.md) - [Chinese Remainder Theorem](https://www.ctfrecipes.com/cryptography/general-knowledge/maths/modular-arithmetic/chinese-remainder-theorem.md) - [Modular binomial](https://www.ctfrecipes.com/cryptography/general-knowledge/maths/modular-arithmetic/modular-binomial.md) - [Padding](https://www.ctfrecipes.com/cryptography/general-knowledge/padding.md) - [PKCS#7](https://www.ctfrecipes.com/cryptography/general-knowledge/padding/pkcs-7.md) - [Misc](https://www.ctfrecipes.com/cryptography/misc.md) - [XOR](https://www.ctfrecipes.com/cryptography/misc/xor.md) - [Mono-alphabetic substitution](https://www.ctfrecipes.com/cryptography/mono-alphabetic-substitution.md) - [Index of coincidence](https://www.ctfrecipes.com/cryptography/mono-alphabetic-substitution/index-of-coincidence.md) - [frequency analysis](https://www.ctfrecipes.com/cryptography/mono-alphabetic-substitution/frequency-analysis.md) - [Well known algorithms](https://www.ctfrecipes.com/cryptography/mono-alphabetic-substitution/well-known-algorithms.md) - [Scytale](https://www.ctfrecipes.com/cryptography/mono-alphabetic-substitution/well-known-algorithms/scytale.md): Spartan cipher - [ROT](https://www.ctfrecipes.com/cryptography/mono-alphabetic-substitution/well-known-algorithms/rot.md): Caesar & ROT13 - [Polybe](https://www.ctfrecipes.com/cryptography/mono-alphabetic-substitution/well-known-algorithms/polybe.md): Cipher square - [Vigenere](https://www.ctfrecipes.com/cryptography/mono-alphabetic-substitution/well-known-algorithms/vigenere.md) - [Pigpen cipher](https://www.ctfrecipes.com/cryptography/mono-alphabetic-substitution/well-known-algorithms/pigpen-cipher.md): Masonic cipher - [Affine cipher](https://www.ctfrecipes.com/cryptography/mono-alphabetic-substitution/well-known-algorithms/affine-cipher.md) - [Symmetric Cryptography](https://www.ctfrecipes.com/cryptography/symmetric-cryptography.md) - [AES](https://www.ctfrecipes.com/cryptography/symmetric-cryptography/aes.md): The Rijndael scheme - [Block Encryption procedure](https://www.ctfrecipes.com/cryptography/symmetric-cryptography/aes/block-encryption-procedure.md) - [Byte Substitution](https://www.ctfrecipes.com/cryptography/symmetric-cryptography/aes/block-encryption-procedure/byte-substitution.md) - [Shift Row](https://www.ctfrecipes.com/cryptography/symmetric-cryptography/aes/block-encryption-procedure/shift-row.md) - [Mix Column](https://www.ctfrecipes.com/cryptography/symmetric-cryptography/aes/block-encryption-procedure/mix-column.md) - [Add Key](https://www.ctfrecipes.com/cryptography/symmetric-cryptography/aes/block-encryption-procedure/add-key.md) - [Key Expansion / Key Schedule](https://www.ctfrecipes.com/cryptography/symmetric-cryptography/aes/block-encryption-procedure/key-expansion-key-schedule.md) - [Mode of Operation](https://www.ctfrecipes.com/cryptography/symmetric-cryptography/aes/mode-of-operation.md) - [ECB](https://www.ctfrecipes.com/cryptography/symmetric-cryptography/aes/mode-of-operation/ecb.md): Electronic Codebook Block - [Block shuffling](https://www.ctfrecipes.com/cryptography/symmetric-cryptography/aes/mode-of-operation/ecb/block-shuffling.md) - [Challenge example](https://www.ctfrecipes.com/cryptography/symmetric-cryptography/aes/mode-of-operation/ecb/block-shuffling/challenge-example.md): Arbitrary token - [ECB Oracle](https://www.ctfrecipes.com/cryptography/symmetric-cryptography/aes/mode-of-operation/ecb/ecb-oracle.md) - [Challenge example](https://www.ctfrecipes.com/cryptography/symmetric-cryptography/aes/mode-of-operation/ecb/ecb-oracle/challenge-example.md) - [CBC](https://www.ctfrecipes.com/cryptography/symmetric-cryptography/aes/mode-of-operation/cbc.md): Cipher Block Chaining - [Bit flipping](https://www.ctfrecipes.com/cryptography/symmetric-cryptography/aes/mode-of-operation/cbc/bit-flipping.md) - [Challenge example](https://www.ctfrecipes.com/cryptography/symmetric-cryptography/aes/mode-of-operation/cbc/bit-flipping/challenge-example.md) - [Padding oracle](https://www.ctfrecipes.com/cryptography/symmetric-cryptography/aes/mode-of-operation/cbc/padding-oracle.md) - [Challenge example](https://www.ctfrecipes.com/cryptography/symmetric-cryptography/aes/mode-of-operation/cbc/padding-oracle/challenge-example.md) - [OFB](https://www.ctfrecipes.com/cryptography/symmetric-cryptography/aes/mode-of-operation/ofb.md): Output Feedback - [Key stream reconstruction](https://www.ctfrecipes.com/cryptography/symmetric-cryptography/aes/mode-of-operation/ofb/key-stream-reconstruction.md) - [Encrypt to Uncrypt](https://www.ctfrecipes.com/cryptography/symmetric-cryptography/aes/mode-of-operation/ofb/encrypt-to-uncrypt.md): Encrypt + Encrypt = plaintext --- # Agent Instructions: Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. 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