Private.Ki Encryption Explained

Privacy is the core of Private.Ki, and that starts with robust encryption. We use End-to-End Encryption (E2EE) for everything: Content and metadata.

That means: All messages are encrypted on your device and can only be decrypted by the intended recipient’s device. We also use secure storage for all of your user data.

No one else can read your messages. Not even we can. (And we don't want to.)

In detail:

  • All emails and chats are encrypted on your device with the recipients' public PGP key. All content that is sent to the Private.Ki servers is fully encrypted, nothing is sent in cleartext.
  • Only the recipient can decrypt the message with his secret PGP key on his device.
  • No content is ever saved anywhere in a non-encrypted form.
  • PGP secret keys can only be unlocked by entering a secure passphrase on the client side (which is never exposed to the server), or by using a secure method to replace the passphrase.
  • Drafts are encrypted with AES.
  • Non-encrypted external incoming messages are encrypted with PGP (with the recipient's PGP public key). They are never stored anywhere in non-encrypted form. After they have been opened once, they are encrypted with AES.
  • Encrypted external incoming messages are encrypted again with the recipient's PGP public key (double layer PGP).
  • All metadata is encrypted.

In practice, all emails and chats use PGP encryption automatically. If you exchange messages with another Private.Ki user, the encryption is seamless – your app encrypts everything (including message text and attachments) before it reaches our servers, and you don't have to do anything special.

Importantly, Private.Ki also encrypts metadata wherever possible. Typical email metadata like sender, recipient, subject, and timestamps can reveal a lot about your communication patterns. With Private.Ki, when you communicate with another Private.Ki user, even the sender/recipient fields and subject line are encrypted on the client side.

Only the minimum routing info is exposed (for example, the server needs to know the recipient’s address to deliver the message, but your address is encrypted).

For emails exchanged with external services, metadata has to be handled by standard email protocols briefly, but we never store it in plaintext. It’s held only in memory as needed for delivery and then encrypted and purged.

Beyond content encryption, Private.Ki employs obfuscation techniques to protect your privacy. We may add random padding to messages and use uniform timing intervals for network requests, which helps mask patterns like message size or sending frequency. his makes it harder for eavesdroppers to glean information from encrypted traffic (for instance, they cannot easily tell if you sent a large attachment or if you send messages on a schedule).

We also maintain a strict no-log policy: We do not keep identifying logs of your usage or IP addresses (more on this in Data Safety & Transparency).

This is only a brief overview - read the detailed description of our encryption here.