VPN4ALL Cryptobrowser is a free addon for the Chrome browser to encrypt and decrypt email communications with AES256-bit. It works with any web based email service, like Yandex, Gmail and Yahoo, and it can also be used to post encrypted messages to securely communicate with your friends in social media platforms like Facebook or Linked In, exchanging encrypted private messages.
After installing this addon you will see a new button in your browser labelled number 4. To encrypt an email all you have to do is to highlight the text you would like to secure, right click and choose “Encrypt“, Cryptobrowser’s password box will then open allowing you to choose a password or generate a random one.
You can save this password in the same box so you don’t have to write it down and a meter will let you know if it is strong or weak word.
Cryptobrowser is promoting this addon as a way to stop the NSA from spying on you but I don’t think it can do that since there is the possibility that automatically saved drafts in Gmail servers could be accessed by the NSA. For real security you should not compose any sensitive email message in your web mail, and Cryptobrowser unfortunately does not work off the browser.
The second problem I see with this encryption addon is that you need to convey the password to the receiver for him to be able to decrypt the message and you can’t use the addon to do this. Calling someone over the phone to tell them the password is possible, but then, if you are subject to state surveillance your phone will possibly be wiretapped. A third problem is that file attachments can not be encrypted, the addon only works with text.
Cyptobrowser makes it easy to encrypt and decrypt emails, but due to the reasons outlined above, I would not trust it to secure my communications against state surveillance. In fairness to them, encryption browser addons all fall foul of the automatically saved drafts problem.
If you want to beat the NSA is best to encrypt everything offline and then copy and paste the message in your webmail. An uncomplicated solution to do this would be to store your message inside a password protected .rar or .7zip file.