| Bastille | | System hardening tool focusing on educating the user |
| CSP | | Simple PKI Toolkit |
| CoolKey | | Driver support for the CoolKey and CAC products |
| EasyPG | | GnuPG interface for emacs |
| GNUMail-pgp (V) | | Bundle for PGP support in GNUMail |
| HElib | | Homeomorphic Encryption library |
| KeePass | | Free, open source, light-weight and easy-to-use password manager |
| MyPasswordSafe | | Easy-to-use password manager |
| PAM | | Pluggable Authentication Modules (PAM) |
| aide | | Free intrusion detection system for checking file integrity |
| aide06 | | Older intrusion detection system for checking file integrity |
| aircrack-ng (V) | | Tools for auditing wireless networks |
| airsnort (V) | | WLAN sniffer and realtime WEP cracker |
| amap | | Applications and Services scanner |
| antonym | | Anonymous nymserver account maintenance tool |
| ap-modsecurity | | Intrusion detection and prevention engine for web applications |
| ap-modsecurity2 | | Intrusion detection and prevention engine for web applications |
| apg | | Tool set for random password generation |
| arirang | | Powerful webserver security scanner |
| avcheck | | Mail content filter for SMTP servers |
| base | | Analysis engine to process a database of security events |
| bcrypt | | Cross platform file encryption utility |
| beecrypt | | Multipurpose cryptographic library |
| bitstir | | Entropy restoration daemon |
| botan | | Portable, easy to use, and efficient C++ crypto library |
| caff | | Various GnuPG related tools |
| ccid | | Middleware to access a smart card using SCard API (PC/SC) |
| cfs | | Encrypting file system, using NFS as its interface |
| chkrootkit | | Locally checks for signs of a rootkit |
| cityhash (V) | | Provides hash functions for strings |
| clamav | | Anti-virus toolkit |
| clusterssh | | Cluster administration tool |
| courier-authlib | | Courier Authentication Library |
| crack | | The Sensible Unix Password Cracker |
| crypto++ | | Free C++ class library of Cryptographic Primitives |
| cvm | | Credential Validation Modules |
| cy2-anonymous | | Cyrus SASL ANONYMOUS authentication plugin |
| cy2-crammd5 | | Cyrus SASL CRAM-MD5 authentication plugin |
| cy2-digestmd5 | | Cyrus SASL DIGEST-MD5 authentication plugin |
| cy2-gssapi | | Cyrus SASL GSSAPI authentication plugin |
| cy2-ldapdb | | Cyrus SASL LDAPDB authentication plugin |
| cy2-login | | Cyrus SASL LOGIN authentication plugin |
| cy2-ntlm | | Cyrus SASL NTLM authentication plugin |
| cy2-otp | | Cyrus SASL OTP authentication plugin |
| cy2-plain | | Cyrus SASL PLAIN authentication plugin |
| cy2-saml | | Crude SAML assertion validator for bridging WebSSO and SASL |
| cy2-scram | | Cyrus SASL SCRAM authentication plugin |
| cy2-sql | | Cyrus SASL SQL authentication plugin |
| cyrus-sasl | | Simple Authentication and Security Layer |
| cyrus-saslauthd | | Cyrus SASL plaintext authentication daemon |
| ddos-scan | | Scan for a limited set of distributed denial of service (ddos) agents |
| destroy | | Program to securely destroy files on the hard disk |
| dhbitty | | Small public key ECDH encryption/decryption program |
| dirb | | Web Content Scanner |
| dirmngr | | X509 certificate and CRL downloader |
| dnssec-tools | | Toolkit to ease the deployment of DNSSEC related technologies |
| dropbear | | Small SSH2 server and client, aimed at embedded market |
| dsniff | | Password sniffer (webspy) |
| dsniff-nox11 | | Password sniffer |
| egd | | EGD: Entropy Gathering Daemon |
| engine-pkcs11 | | PKCS#11 engine for OpenSSL |
| ent | | Entropy calculation and analysis of putative random sequences |
| ettercap (V) | | Multipurpose sniffer/interceptor/logger for switched LAN |
| f-prot-antivirus6-fs-bin | | F-PROT antivirus for File Servers |
| f-prot-antivirus6-ms-bin | | F-PROT antivirus for Mail Servers |
| f-prot-antivirus6-ws-bin | | F-PROT antivirus for workstations |
| flawfinder | | Python program to find flaws in C/C++ programs |
| fprint-demo | | Simple GTK+ application to demonstrate libfprint's capabilities |
| fragroute | | Tool for intercepting, modifying and rewriting egress traffic |
| fsh | | Fast remote command execution |
| fwbuilder | | Firewall Builder GUI |
| gnome-keyring | | GNOME password and secret manager |
| gnome-keyring-manager | | GNOME password and secret manager |
| gnome-keyring-sharp | | Mono implementation of gnome-keyring |
| gnu-crypto | | GPL implementation of the Java Crypto Extensions |
| gnupg | | GNU Privacy Guard, public-Key encryption and digital signatures |
| gnupg-pkcs11-scd | | OpenSC smart card support for GnuPG |
| gnupg2 | | GNUpg with OpenPGP and S/MIME capabilities |
| gnutls | | GNU Transport Layer Security library |
| google-authenticator | | One-time password generator and PAM module from Google |
| gpa | | GUI frontend to gnupg |
| gpass | | GNOME Password Manager |
| gpg2dot | | Converts your GnuPG keyring to a graph of associations |
| gpgme | | GnuPG Made Easy |
| gps (V) | | Ghost Port Scan |
| gsasl | | GNU implementation of the Simple Authentication and Security Layer |
| gss | | GNU Generic Security Service Library |
| gtk-systrace | | GTK interface to systrace(1) |
| hackbot | | Vulnerability scanner written in Perl |
| hashcash | | Hash collision based postage stamp |
| heimdal | | Kerberos 5 implementation |
| heirloom-su | | Collection of standard Unix utilities (su) |
| honeyd | | Small daemon that creates virtual hosts on a network |
| honeyd-arpd | | ARP daemon for honeyd |
| hydan | | Steganography tool for covert comms, signing and watermarking |
| hydra | | Login password cracker |
| ike-scan | | Fingerprinting IKE implementation |
| ipsec-tools | | IPsec-tools racoon IKE daemon |
| ipv6-toolkit | | IPv6 security assessment and troubleshooting tool |
| isakmpd | | OpenBSD IKE daemon |