libscrypt implements scrypt key derivation function. It is designed to be far more secure against hardware brute-force attacks than alternative functions such as PBKDF2 or bcrypt.

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.

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).

hash_extender is a utility for performing hash length extension attacks supporting MD4, MD5, RIPEMD-160, SHA-0, SHA-1, SHA-256, SHA-512, and WHIRLPOOL hashes.

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.

The Olm library implements the Double Ratchet cryptographic ratchet. It is written in C and C++11, and exposed as a C API.

Tomb is an application to manage the creation and access of encrypted storage files: it can be operated from commandline and it can integrate with a user's graphical desktop.

This package provides a cryptographic hash function that is fast, secure, parallelizable, capable of incremental updates.

libb2 is a portable implementation of the BLAKE2 family of cryptographic hash functions. It includes optimised implementations for IA-32 and AMD64 processors, and an interface layer that automatically selects the best implementation for the processor it is run on.

BLAKE2 (RFC 7693) is a family of high-speed cryptographic hash functions that are faster than MD5, SHA-1, SHA-2, and SHA-3, yet are at least as secure as the latest standard, SHA-3. It is an improved version of the SHA-3 finalist BLAKE.

The currently provided message digest algorithms are:

• MD2

• MD4

• MD5

• RIPEMD-160

• SHA-1

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

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.

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.

This module is intended to provide a cryptographically-secure replacement for Perl's built-in rand function. "Cryptographically secure", in this case, means:

1. No matter how many numbers you see generated by the random number generator, you cannot guess the future numbers, and you cannot guess the seed.

2. There are so many possible seeds that it would take decades, centuries, or millennia for an attacker to try them all.

3. The seed comes from a source that generates relatively strong random data on your platform, so the seed itself will be as random as possible.

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.

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.

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.

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 package provides b3sum, a command line checksum tool based on the BLAKE3 cryptographic hash function.

The Olm library implements the Double Ratchet cryptographic ratchet. This package contains its Python bindings.

BLAKE2 is a cryptographic hash function faster than MD5, SHA-1, SHA-2, and SHA-3, yet is at least as secure as SHA-3.

Intel QuickAssist Technology provides hardware acceleration for offloading security, authentication and compression services from the CPU, thus significantly increasing the performance and efficiency of standard platform solutions. Its services include symmetric encryption and authentication, asymmetric encryption, digital signatures, RSA, DH and ECC, and lossless data compression. This package provides user space libraries that allow access to Intel QuickAssist devices and expose the Intel QuickAssist APIs and sample codes.

CRC++ is a C++ library for calculating cyclic redundancy checks. It supports bit-by-bit and byte-by-byte calculation of full and multipart CRCs. It aims to have highly optimized algorithms that can run branchless for projects with a need for efficiency. Many common CRCs are provided out-of-the-box, such as CRC-32 (used in PKZip and Ethernet), CRC-XMODEM, and CRC-CCITT.

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.

Sodium is a new easy-to-use high-speed software library for network communication, encryption, decryption, signatures, etc.