OpenSSL

The OpenSSL Project is a collaborative effort to develop a robust, commercial-grade, full-featured, and Open Source toolkit implementing the Secure Sockets Layer (SSL v2/v3) and Transport Layer Security (TLS v1) protocols as well as a full-strength general purpose cryptography library. The project is managed by a worldwide community of volunteers that use the Internet to … Read more

GnuPG

Some of basic informations, from http://www.gnupg.org/ site:

GnuPG is the GNU project‘s complete and free implementation of the OpenPGP standard as defined by
RFC4880. GnuPG allows to encrypt and sign your data and communication, features a versatile key managment system as well as access modules for all kind of public key directories. GnuPG, also known asGPG, is a command line tool with features for easy integration with other applications. A wealth of frontend applications and
libraries are available. Version 2 of GnuPG also provides support for S/MIME.

GnuPG is Free Software (meaning that it respects your freedom). It can be freely used, modified and distributed under the terms of the GNU General Public License.

GnuPG comes in two flavours:
1.4.10 is the well known and portable standalone version, whereas
2.0.15 is the enhanced and somewhat harder to build version.

Project Gpg4win provides a Windows version of GnuPG. It is nicely integrated into an installer and features several frontends as well as (German) manuals.

Project Aegypten developed the S/MIME functionality in GnuPG 2.

Diceware

Dice Logo

“This page offers a better way to create a strong, yet easy to remember passphrase for use with encryption and security programs. Weak passwords and passphrases are one of the most common flaws in computer security. Take a few minutes and learn how to do it right. The information presented here can be used by anyone.”

This is cite from original home page of Diceware Passphrase: http://world.std.com/~reinhold/diceware.html

GnuPG

The GNU Privacy Guard GnuPG is a complete and free implementation of the OpenPGP standard as defined by RFC4880 (also known as PGP). GnuPG allows to encrypt and sign your data and communication, features a versatile key management system as well as access modules for all kinds of public key directories. GnuPG, also known as … Read more

Diceware

Dice

“This page offers a better way to create a strong, yet easy to remember passphrase for use with encryption and security programs. Weak passwords and passphrases are one of the most common flaws in computer security. Take a few minutes and learn how to do it right. The information presented here can be used by … Read more