OpenBSD tool to sign and verify signatures on files. Portable version which uses libbsd.
PyCryptodome is a self-contained Python package of low-level cryptographic primitives. It supports Python 2.6 and 2.7, Python 3.4 and newer, and PyPy. It assumes that you know what you're doing, so this is not a safe-to-use module. The Cryptographic Best Practices website should be open at the same time.
Minisign is a dead simple tool to sign files and verify signatures. It is portable, lightweight, and uses the highly secure Ed25519 public-key signature system. Requires libsodium.
tcpxtract is a tool for extracting files from network traffic based on file signatures.
Taglines! Taglines to feed the QWKmail readers of the Illuminati!