> For the complete documentation index, see [llms.txt](https://libsodium.gitbook.io/doc/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://libsodium.gitbook.io/doc/secret-key_cryptography.md).

# Secret-key cryptography

- [Authenticated encryption](https://libsodium.gitbook.io/doc/secret-key_cryptography/secretbox.md)
- [Encrypted streams and file encryption](https://libsodium.gitbook.io/doc/secret-key_cryptography/secretstream.md)
- [Encrypting a set of related messages](https://libsodium.gitbook.io/doc/secret-key_cryptography/encrypted-messages.md)
- [Authentication](https://libsodium.gitbook.io/doc/secret-key_cryptography/secret-key_authentication.md)
- [AEAD constructions](https://libsodium.gitbook.io/doc/secret-key_cryptography/aead.md)
- [ChaCha20-Poly1305](https://libsodium.gitbook.io/doc/secret-key_cryptography/aead/chacha20-poly1305.md)
- [Original ChaCha20-Poly1305 construction](https://libsodium.gitbook.io/doc/secret-key_cryptography/aead/chacha20-poly1305/original_chacha20-poly1305_construction.md)
- [IETF ChaCha20-Poly1305 construction](https://libsodium.gitbook.io/doc/secret-key_cryptography/aead/chacha20-poly1305/ietf_chacha20-poly1305_construction.md)
- [XChaCha20-Poly1305 construction](https://libsodium.gitbook.io/doc/secret-key_cryptography/aead/chacha20-poly1305/xchacha20-poly1305_construction.md)
- [AEGIS-256](https://libsodium.gitbook.io/doc/secret-key_cryptography/aead/aegis-256.md)
- [AEGIS-128L](https://libsodium.gitbook.io/doc/secret-key_cryptography/aead/aegis-128l.md)
- [AES256-GCM](https://libsodium.gitbook.io/doc/secret-key_cryptography/aead/aes-256-gcm.md)
- [AES256-GCM with precomputation](https://libsodium.gitbook.io/doc/secret-key_cryptography/aead/aes-256-gcm/aes-gcm_with_precomputation.md)
- [IP address encryption](https://libsodium.gitbook.io/doc/secret-key_cryptography/ip_address_encryption.md)