Botan is a crypto library written in C++. It provides a variety of cryptographic algorithms, including common ones such as AES, MD5, SHA, HMAC, RSA, Diffie-Hellman, DSA, and ECDSA, as well as many others that are more obscure or specialized. It also offers SSL/TLS (client and server), X.509v3 certificates and CRLs, and PKCS #10 certificate requests. A message processing system that uses a filter/pipeline metaphor allows for many common cryptographic tasks to be completed with just a few lines of code. Assembly and SIMD optimizations for common CPUs offers speedups for critical algorithms like AES and SHA-1.
CACKey provides a standard interface (PKCS#11) for smartcards connected to a PC/SC compliant reader. It performs a similar function to "CoolKey", but only supports Government Smartcards. It supports all Government Smartcards that implement the Government Smartcard Interoperability Specification (GSC-IS) v2.1 or newer.
cpm (Console Password Manager) is a small console tool to manage passwords and other sensitive data and store them in a public-key encrypted file. It also allows you to configure the whole hierarchy yourself, so it's easily adoptable for many requirements. The encryption is handled through GnuPG, and the data inside is stored as XML.
CyaSSL is a C-language-based SSL library targeted for embedded and RTOS environments, primarily because of its small size and speed. CyaSSL supports the industry standards up to the current TLS 1.2 level, is up to 20 times smaller than OpenSSL, includes SSL client libraries and an SSL server implementation, includes an OpenSSL compatibility layer, and offers several progressive ciphers such as RABBIT and HC-128. Dual licensed under both the GPLv2 and standard commercial licensing, it caters to a wide range of projects.
CyberFusion is a system that provides secure file transfer across a LAN, a WAN, and the Internet. It offers encryption and security, reliability and guaranteed delivery, management and automation, audit and control. It offers cost-saving migration from competitor products such as Connect:Direct which is supported with useful tools. It may be used as part of a VPN, ERP, EAI, or ETL software solution for secure file transfers as well as in disaster recovery, data archive, and backup and restore operations.
Dar is a shell command that makes backup of a directory tree and files. Its features include splitting archives over several files, DVD, CD, ZIP, or floppies, compression, full or differential backups, strong encryption, proper saving and restoration of hard links, extended attributes, file forks, Door inodes, and sparse files, remote backup using pipes and external commands (such as ssh), and rearrangement of the "slices" of an existing archive. It can run commands between slices, before and after saving some defined files or directories (for a proper database backup, for example), and quickly retrieve individual files from differential and full backups. Several external GUIs exist as alternatives to its CLI interface, like kdar, DarGUI, SaraB, etc.
Email sends email to remote SMTP servers via the command line, which makes it useful in cron jobs. It will send to any RFC standard remote ESMTP server, is TLS/SSL enabled, and will allow you to encrypt, sign, and design your message on the fly. It has the capability to use signature files with dynamic options, address book functionality, and users can also attach pictures, binary files, documents, or whatever they want. It is completely compatible with GNUPG for encryption and signing, and is easy to configure and use.
FlexiCA is a certification authority tool. It is implemented using Java and the Eclipse Rich Client Platform. FlexiCA is extensible and supports RSA, DSA, and Elliptic Curve cryptography out of the box. Other crypto-systems may be added easily, if ASN.1 structures for encoding are available. All cryptographic functions are provided by FlexiProvider.
GNUnet is a peer-to-peer framework with focus on providing security. All peer-to-peer messages in the network are confidential and authenticated. The framework provides a transport abstraction layer and can currently encapsulate the network traffic in UDP, TCP, HTTP, HTTPS, or direct 802.11 (WLAN). GNUnet supports accounting to provide contributing nodes with better service. The services built on top of the framework include anonymous file sharing and a virtual network providing IPv4-IPv6 transition via protocol translation over the P2P network.