Yahoo showcased its encrypted email service at the South by Southwest festival in Austin, Texas, by adding end-to-end (e2e) encryption plugin for Yahoo Mail.

Yahoo chief information security officer Alex Stamos highlighted that the new service is designed to allow anyone to send scrambled email messages that cannot even be decoded by the company.

However, Stamos also made it clear that the service will not encrypt every aspect of the email as information regarding the recipient’s subject line and time will be readable in order to route the message properly across the internet.

Stamos said: "There is a wide spectrum of use for e2e encryption, ranging from the straightforward (sharing tax forms with an accountant), to the potentially life-threatening (emailing in a country that does not respect freedom of expression).

"Wherever you land on the spectrum, we’ve heard you loud and clear: We’re building the best products to ensure a more secure user experience and overall digital ecosystem."

The company has also released the Yahoo specific e2e encryption plug-in source code on GitHub, and it expects the encrypted email service to be available to users by the end of 2015.

According to Stamos, ‘search’ feature, is one the most used function in email systems, which is often used more often than writing emails, and searching the text of thousands of messages will become difficult if the data is encrypted.

According reports, Yahoo’s encryption is faster than the currently used system working on a version of PGP "pretty good privacy" encryption.

Stamos demonstrated the company’s system by sending the message in a minute using encrypted Yahoo tool, which was half the time it took for Stamos to encrypt and send a message using traditional PGP tools.