Messages are encrypted at all times
Messages are stored on ProtonMail servers in encrypted format. They are also transmitted in encrypted format between our servers and user devices. Messages between ProtonMail users are also transmitted in encrypted form within our secure server network. Because data is encrypted at all steps, the risk of message interception is largely eliminated.
Zero Access to User Data
Your encrypted data is not accessible to us
ProtonMail’s segregated authentication and decryption system means logging into a ProtonMail private email account requires two passwords. The first password is used to verify the identity of the user. After that, encrypted data can be retrieved. The second password is a decryption password which is never sent to us. It is used to decrypt data on your device so we do not have access to the decrypted data, or the decryption password. This means we cannot hand over your data to third parties. For this reason, we are also unable to do decryption password recovery. If you forget your decryption password, we cannot recover your data.
Open Source Cryptography
Time-tested and trusted encryption algorithms
We use only secure implementations of AES, RSA, along with OpenPGP. Furthermore, all of the cryptographic libraries we use are open source. By using open source libraries, we can guarantee that the encryption algorithms we are using do not have clandestinely built in back doors. ProtonMail's open source software has been thoroughly vetted by security experts from around the world to ensure the highest levels of protection.Learn about ProtonMail and Open Source