> For the complete documentation index, see [llms.txt](https://www.ctfrecipes.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://www.ctfrecipes.com/cryptography/general-knowledge.md).

# General knowledge

- [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)