The OpenCA Project is a collaborative effort to develop a robust, full-featured and Open Source out-of-the-box Certification Authority implementing the most used protocols with full-strength cryptography world-wide. OpenCA is based on many Open-Source Projects. Among the supported software is OpenLDAP, OpenSSL, Apache Project, Apache mod_ssl.
CKS is an openPGP (RFC2440) compliant public key server. It is currently under development. It is written in C, and runs on Linux. It uses PostgreSQL for key storage, and supports the hkp protocol (it can interface with GnuPG and NAI PGP). The keyserver is mostly functional, and there is a link to a running copy on the homepage.
SecureSkat is a peer-to-peer implementation of the German card game Skat. The program negotiates participating players and game sessions over an arbitrary IRC network (Internet Relay Chat). Neither a trusted third-party (dealer) nor a centralized game server is necessary. All critical operations, e.g. shuffle of the deck, are performed using advanced cryptographic techniques (so-called Mental Poker solutions) provided by LibTMCG. The outdated OpenSkat branch contains a graphical user interface based on XSkat 3.4. This interface can be used with most recent versions, but must be built separately.
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.
Endian Firewall is an all-in-on Linux security distribution that turns any system into a full-featured security appliance. It features a stateful packet inspection firewall, application-level proxies for various protocols (HTTP, POP3, SMTP), anti-virus support, virus and spam filtering for email traffic (POP and SMTP), content filtering of Web traffic, and a "hassle free" VPN system based on OpenVPN.
EverCrack is a cryptanalysis engine. The overall design goal is to systematically break down complex ciphers into their simplex components for cryptanalysis (by the kernel). The kernel consists of an algebraic design (comparison and reduction) for breaking uniliteral, monoalphabetic ciphers instantaneously. Currently, it can break a 4000-word cipher in milliseconds. EverCrack currently has multi-language support for the user interface and cracking encryption in other language dictionaries (English, German, French, Spanish, Italian, Swedish, Dutch, and Portuguese).
cryptmount is a utility for creating and managing secure filing systems on GNU/Linux systems. After initial setup, it allows any user to mount or unmount filesystems on demand, solely by providing the decryption password, with any system devices needed to access the filing system being configured automatically. A wide variety of encryption schemes (provided by the kernel dm-crypt system and the libgcrypt library) can be used to protect both the filesystem and the access key. The protected filing systems can reside in either ordinary files or disk partitions. The package also supports encrypted swap partitions, and automatic configuration on system boot-up.