Lasso (Liberty Alliance Single Sign On) is an implementation of the Liberty Alliance specifications. These specifications define protocols for federated identities, single sign-on, etc. Lasso supports ID-FF 1.2, SAML 2.0, and parts of ID-WSF. It provides both a C library and bindings for several languages (Python, Java, Perl, PHP 4, and PHP 5).
A reasonable way to achieve a long term backup of OpenPGP (GnuPG, PGP, etc) keys is to print them out on paper. Due to metadata and redundancy, OpenPGP secret keys are significantly larger than just the "secret bits". In fact, the secret key contains a complete copy of the public key. Since the public key generally doesn't need to be backed up in this way (most people have many copies of it on various keyservers, Web pages, etc), only extracting the secret parts can be a real advantage. Paperkey extracts just those secret bytes and prints them. To reconstruct, you re-enter those bytes (whether by hand or via OCR), and paperkey can use them to transform your existing public key into a secret key.
Enigmail is an extension for the mail client of Mozilla, Netscape 7.x, and Mozilla Thunderbird that allows users to access the authentication and encryption features provided by the popular GnuPG software. It can encrypt/sign mail when sending, decrypt/authenticate received mail, and import/export public keys. It supports both the inline PGP format and the PGP/MIME format, which can be used to encrypt attachments, and is cross-platform, although binaries are supplied only for a limited number of platforms. Enigmail uses inter-process communication to execute GPG to carry out encryption/authentication.
Zebedee is a simple program to establish an encrypted, compressed tunnel for TCP/IP or UDP data transfer between two systems. This allows traffic such as telnet, FTP, and X to be protected from snooping as well as potentially gaining performance over low-bandwidth networks from compression.
ACL2 is a mathematical logic, programming language, and mechanical theorem prover based on the applicative subset of Common Lisp. It is an "industrial-strength" version of the NQTHM or Boyer/Moore theorem prover, and has been used for the formal verification of commercial microprocessors, the Java Virtual Machine, interesting algorithms, and so forth.
PolarSSL is a light-weight cryptographic and SSL/TLS library written in C. PolarSSL makes it easy for developers to include cryptographic and SSL/TLS capabilities in their (embedded) applications with as little hassle as possible. Loose coupling of the components inside the library means that it is easy to separate the parts that are needed, without needing to include the total library. PolarSSL is written with embedded systems in mind and has been ported on a number of architectures, including ARM, PowerPC, MIPS, and Motorola 68000. The source is written to have very loose coupling, enabling easy integration of parts in other software projects. Very loosely coupled cryptographic algorithms for MD2, MD4, MD5, SHA1, SHA-256, SHA-512, AES, Camellia, DES, Triple DES, ARC3, and RSA are included.
TnFOX is a modern secure, robust, multithreaded, exception aware, internationalizable, portable GUI toolkit library designed for mission-critical work in C++ and Python, forked from the FOX library. It replicates the Qt API in many places, comes with a full set of Python bindings, and has been designed primarily for Tn, the port of Tornado to FOX.