I'm looking for a windows application to just encrypt some plaintext destined for a single user whose public key I have. I imagine something with just two text areas where one is the plaintext, then you select the public key of the recipient and then the text gets encrypted in the ciphertext area.

The idea is to then just copy paste the ciphertext in an email (gmail specifically, so any email client integration would need to be in a browser). The main requirement is that it should be very simple to use since it is going to be used by non-experts.

The workflow should be something like

  1. Install & open application
  2. generate personal keys
  3. import public key of the recipients
  4. type plaintext
  5. select (single) recipient
  6. get ciphertext

I have seen similar apps that use passwords to encrypt the text, but I am looking for something using public-key cryptography to validate identities. I've also seen other apps where you have to install gpg + browser extension but again, I need something simple: one single app even if not super integrated with a web mail service (copy pasting from the app is fine). Another problem i've seen is that they parse the gmail DOM to inject the text so whenever gmail changes its layout, the extension stops working

Any good recommendations? hopefully opensource

1 Answer 1


if your chosen cryptography system is public-key based, you will probably use OpenPGP (RFC 4880).

THE implementation of this standard is GnuPG/GPG and its plain version (without a GUI) you will find on its homepage... but for windows an other project called Gpg4win is also providing an installer for a full featured version with a GUI, explorer-plugin, outlook-plugin, etc., which i guess is the one most users are looking for.

if it has not to be a "windows-app", since you just want to use it for sending text via webmail, maybe Mailvelope is the easier solution you are looking for.

  • perfect, thank you. sadly mailvelope doesn't support encrypting attachments yet
    – Hilikus
    Commented May 22, 2015 at 16:13
  • yes that's right! -- preventively: with OpenPGP the mail-header (including the subject) isn't encrypted! Commented May 22, 2015 at 22:23
  • 1
    There are also well hidden official GnuPG Windows binaries that are imho much better than Gpg4Win. Commented Nov 18, 2017 at 9:02

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.