Optimized C library for cryptographic operations on curve secp256k1.

This library is used for consensus critical cryptographic operations on the Bitcoin Cash network.

Features:

• secp256k1 ECDSA signing/verification and key generation.

• secp256k1 Schnorr signing/verification (Bitcoin Cash Schnorr variant).

• Additive and multiplicative tweaking of secret/public keys.

• Serialization/parsing of secret keys, public keys, signatures.

• Constant time, constant memory access signing and pubkey generation.

• Derandomized ECDSA (via RFC6979 or with a caller provided function).

• Very efficient implementation.

• Suitable for embedded systems.

• Optional module for public key recovery.

• Optional module for ECDH key exchange (experimental).

• Optional module for multiset hash (experimental).

This package provides a simple password-based encryption utility as a demonstration of the scrypt key derivation function. Scrypt is designed to be far more resistant against hardware brute-force attacks than alternative functions such as PBKDF2 or bcrypt.

Transcrypt is a script to configure transparent encryption of sensitive files stored in a Git repository. Files that you choose will be automatically encrypted when you commit them, and automatically decrypted when you check them out. The process will degrade gracefully, so even people without your encryption password can safely commit changes to the repository's non-encrypted files.

Minisign is a dead simple tool to sign files and verify signatures. It is portable, lightweight, and uses the highly secure Ed25519 public-key signature system. Signature written by minisign can be verified using OpenBSD's signify tool: public key files and signature files are compatible. However, minisign uses a slightly different format to store secret keys. Minisign signatures include trusted comments in addition to untrusted comments. Trusted comments are signed, thus verified, before being displayed.

CryFS encrypts your files, so you can safely store them anywhere. It works well together with cloud services like Dropbox, iCloud, OneDrive and others. CryFS creates an encrypted userspace filesystem that can be mounted via FUSE without root permissions. It is similar to EncFS, but provides additional security and privacy measures such as hiding file sizes and directory structure. However CryFS is not considered stable yet by the developers.

mkp224o generates valid ed25519 (hidden service version 3) onion addresses. It allows one to produce customized vanity .onion addresses using a brute-force method.

DigiDoc is an XML file format for documents with digital signatures used by the Estonian ID card infrastructure. This library allows for creation and reading of DigiDoc files.

This module provides implementations for a number of byte-oriented sources of random data.

stoken is a token code generator compatible with RSA SecurID 128-bit (AES) tokens. This package contains a standalone command-line program that allows for importing token seeds, generating token codes, and various utility/testing functions.

Botan is a cryptography library, written in C++11, offering the tools necessary to implement a range of practical systems, such as TLS/DTLS, PKIX certificate handling, PKCS#11 and TPM hardware support, password hashing, and post-quantum crypto schemes. In addition to the C++, botan has a C89 API specifically designed to be easy to call from other languages. A Python binding using ctypes is included, and several other language bindings are available.

Crypto++ is a C++ class library of cryptographic schemes.

Keyutils is a set of utilities for managing the key retention facility in the Linux kernel, which can be used by file systems, block devices, and more to gain and retain the authorization and encryption keys required to perform secure operations.

Asignify offers public cryptographic signatures and encryption with a library or a command-line tool. The tool is heavily inspired by signify as used in OpenBSD. The main goal of this project is to define a high level API for signing files, validating signatures and encrypting using public-key cryptography. Asignify is designed to be portable and self-contained with zero external dependencies. Asignify can verify OpenBSD signatures, but it cannot sign messages in OpenBSD format yet.

The signify utility creates and verifies cryptographic signatures using the elliptic curve Ed25519. This is a Linux port of the OpenBSD tool of the same name.

ISAAC (Indirection, Shift, Accumulate, Add, and Count) is a fast pseudo-random number generator. It is suitable for applications where a significant amount of random data needs to be produced quickly, such as solving using the Monte Carlo method or for games. The results are uniformly distributed, unbiased, and unpredictable unless you know the seed.

This package provides a Perl interface to the ISAAC pseudo random number generator.

The currently provided message digest algorithms are:

• MD2

• MD4

• MD5

• RIPEMD-160

• SHA-1

• SHA-2 (SHA-256, SHA-384 and SHA-512)

ssss-split and ssss-combine are utilities that split and combine secrets securely using Shamir's secret sharing scheme. This implementation allows for a threshold scheme where the minimum number of shares can be less than the total number of shares generated.

Hpenc is a command-line tool for performing authenticated encryption (AES-GCM and ChaCha20-Poly1305) of streaming data. It does not perform an asymmetric key exchange, instead requiring the user to distribute pre-shared keys out of band. It is designed to handle large amounts of data quickly by using all your CPU cores and hardware acceleration.

libxcrypt is a modern library for one-way hashing of passwords. It supports a wide variety of both modern and historical hashing methods: yescrypt, gost-yescrypt, scrypt, bcrypt, sha512crypt, sha256crypt, md5crypt, SunMD5, sha1crypt, NT, bsdicrypt, bigcrypt, and descrypt.

Keychain is usually run from shell profiles like ~/.bash_profile, but it is also possible to use it with non-interactive shells. It works with various operating systems (including GNU/Linux and HURD) and shells (like bourne-compatible, csh-compatible and fish shells). By default Keychain will only start ssh-agent, but it can also be configured to start gpg-agent.

EncFS creates a virtual encrypted file system in user-space. Each file created under an EncFS mount point is stored as a separate encrypted file on the underlying file system. Like most encrypted file systems, EncFS is meant to provide security against off-line attacks, such as a drive falling into the wrong hands.

The libdecaf library is an implementation of elliptic curve cryptography using the Montgomery and Edwards curves Curve25519, Ed25519, Ed448-Goldilocks and Curve448, using the Decaf encoding.

Enchive is a tool to encrypt files to yourself for long-term archival. It's a focused, simple alternative to more complex solutions such as GnuPG or encrypted filesystems. Enchive has no external dependencies and is trivial to build for local use. Portability is emphasized over performance.

Botan is a cryptography library, written in C++11, offering the tools necessary to implement a range of practical systems, such as TLS/DTLS, PKIX certificate handling, PKCS#11 and TPM hardware support, password hashing, and post-quantum crypto schemes. In addition to the C++, botan has a C89 API specifically designed to be easy to call from other languages. A Python binding using ctypes is included, and several other language bindings are available.