Bitcoin is a peer-to-peer electronic cash system that is completely decentralized, without the need for a central server or trusted parties. Users hold the crypto keys to their own money and transact directly with each other, with the help of a P2P network to check for double-spending.
SSLsplit is a tool that performs man-in-the-middle attacks against SSL/TLS encrypted network connections for network forensics and penetration testing. It terminates SSL/TLS and initiates a new connection to the original destination, logging all data transmitted. It supports plain TCP and SSL, HTTP and HTTPS, and IPv4 and IPv6. For SSL and HTTPS, it generates and signs forged X509v3 certificates on-the-fly using the original certificate's subject DN and subjectAltName extension. It supports Server Name Indication, RSA, DSA, and ECDSA keys, and DHE and ECDHE cipher suites. It can also use existing certificates if the private key is available.
Open Transactions is a solid, easy-to-use, financial crypto and digital cash library, including an API, server, and test client. It features anonymous numbered accounts, untraceable digital cash, triple-signed receipts, basket currencies, and signed XML contracts. It also supports cheques, invoices, payment plans, markets with trades, and other instruments. It uses OpenSSL and Lucre blinded tokens.
Wisecracker is a high performance distributed cryptanalysis framework that leverages GPUs and multiple CPUs. It allows security researchers to write their own cryptanalysis tools that can distribute brute-force cryptanalysis work across multiple systems with multiple multi-core processors and GPUs. Security researchers can also use the sample tools provided out-of-the-box. The differentiating aspect of Wisecracker is that it uses OpenCL and MPI together to distribute the work across multiple systems, each having multiple CPUs and/or GPUs.
XCA is an interface for managing RSA and DSA keys, certificates, certificate signing requests, revocation lists and templates. It uses the OpenSSL and Qt4 libraries. Certificates and requests can be created and signed and many x509v3 extensions can be added. XCA supports multiple root and intermediate Certificate authorities. The CAs can be used to create CRLs and extend certificates. The following file-formats are supported: PEM, DER, PKCS#7, PKCS#8, PKCS#10, PKCS#12, and SPKAC.
EncFS is an encrypted pass-through filesystem which runs in userspace on Linux (using the FUSE kernel module). Similar in design to CFS and other pass-through filesystems, all data is encrypted and stored in the underlying filesystem. Unlike loopback filesystems, there is no predetermined or pre-allocated filesystem size.