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Our Tor encrypted email site has a new SSL certificate

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Proton Mail is one of the only email providers that offers email access over Tor. We launched the Proton Mail onion site last year as an extra way to fight surveillance and censorship. Since then, Proton Mail has become banned in at least one country with an authoritarian government(new window), and our onion site provides an important means of access to encrypted email from countries with strong online censorship.

For extra protection, we also use HTTPS encryption for our onion site. Earlier this month, we renewed the SSL certificate for our onion site, which is:

https://protonmailrmez3lotccipshtkleegetolb73fuirgj7r4o4vfu7ozyd.onion/(new window)

Since we launched our onion site in January 2017, leading SSL certificate provider Digicert(new window) has provided us with .onion SSL certificates. Digicert supports strong encryption and is one of the few Certificate Authorities to support onion sites. We are glad to continue our partnership with them.

What is an onion site?

An onion site is a website that can only be reached by using the Tor anonymity network. Tor encrypts your internet connection and routes it through several random servers before it reaches the secret server that houses the Proton Mail onion site.

In this way, internet service providers and governments cannot easily check what’s your IP and location.(new window) It also adds a layer of encryption to your internet connection, above the end-to-end encryption(new window) we useto secure the contents of your messages. We recommend our onion site for users with heightened concerns about surveillance and attack, and also for users in places where the main Proton Mail website is blocked, such as Turkey(new window).

To use our onion site, you must first install Tor on your computer by following the setup instructions(new window). We also provide one-click Tor network access(new window) through Proton VPN, our free VPN service(new window).

HTTPS encryption

While the Tor network automatically encrypts the connection between users’ devices and our servers, we decided to add an extra layer of encryption. The HTTPS encryption we provide in partnership with Digicert offers redundancy in case Tor is ever compromised. It also allows us to protect traffic internally between our servers. You can learn more about our onion site and our decision to use HTTPS encryption here.

With the SSL certificate renewal, users will not notice any changes to their service. When you access our onion site, you will see the green text and lock icon in your browser, indicating the website belongs to Proton AG and that HTTPS encryption is enabled.

Providing encrypted email over Tor is an important part of our mission to protect online freedom(new window). We would like to thank Digicert(new window) and the Tor Project(new window) for their invaluable support.

Fingerprints

SHA-256

34:B6:85:BD:DC:F3:0D:54:55:DD:A3:2C:CF:79:4A:6D:01:87:4D:0C:76:36:1D:C1:F1:8E:4D:99:AC:28:10:AB

SHA-1

74:53:FF:E0:46:15:AB:01:3D:E5:57:C6:84:74:FC:56:81:3D:3A:6C

Sign up and get a free encrypted email(new window) accounts from Proton Mail.

We also provide a free VPN service(new window) to protect your privacy.

Proton Mail and Proton VPN are funded by community contributions. If you would like to support our development efforts, you can upgrade to a paid plan(new window). Thank you for your support!

Secure your emails, protect your privacy
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Ben Wolford(new window)

Ben Wolford is a writer and editor whose work has appeared in major newspapers and magazines around the world. Ben joined Proton in 2018 to help to explain technical concepts in privacy and make Proton products easy to use.

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