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Gpg4win is an installer package for Windows (2000/XP/2003/Vista) with computer programs and handbooks for email and file encryption. Both relevant cryptography standards are supported, OpenPGP and S/MIME. Gpg4win and the software included with Gpg4win are Free Software (among other things free of charge for all commercial and non-commercial purposes).

GPGTools is an open source initiative to bring OpenPGP to Apple OS X in the form of an easy installer package. This allows you to sign, verify, encrypt, and decrypt files and e-mails. Read the introduction to get a detailed idea of how PGP works.

Virtru provides digital privacy technology to let you easily share information securely through all major email programs and applications. Virtru puts you in charge of how your digital information is shared. Combining control, convenience, and simplicity, Virtru makes it easy to keep your private communications private.

Desktop Email Encryption provides an end-to-end email encryption solution that automatically encrypts and decrypts email directly from one user's client to another's without the need to log into a third-party website or by other means.

Lockbin is a web application for sending private email messages and files. People use it to send things like credit card numbers or confidential information.

GPGshell is a Windows GUI for the GNU Privacy Guard - an open source software suite for public-key cryptography compatible with PGP. It provides a simple-ish interface to manage the encryption keys, encrypt and sign files, check the signatures and the like. It is freeware (though, unlike GPG, not free software) and with little effort can be made portable.

p=p is a cyber security solution which protects the confidentiality and reliability of communications for citizens, for public offices and for enterprises.

Providing HIPAA-compliant email, secure email & web services since 1999. Secure communications via email, text, chat, video, and web.

PGPigeon is a simple but powerful OpenPGP-compatible message encryption webapp based on the openpgp.js library.