Lacre is an open source solution to email encryption.
Lacre provides a transparent multiplatform solution to secure all incoming emails. It is based on existing cryptographic standards.
By utilizing the well-known and established PGP protocol, it is compatible with many modern client softwares. This makes Lacre client software agnostic and vendor lock free.
For users: Lacre software provides end-to-end encryption of emails at rest (i.e. when it hits your mailbox) by not storing any private keys on the server. This makes it impossible to decrypt your data without the user’s key.
For admin: Lacre is pluggable. Working as a postfix filter, Lacre does not require an in-house SMTP server solution, but provides seamless integration into your existing infrastructure.
Lacre is open and free!!! By providing an open source solution using existing standards, Lacre enables practically any email provider to offer protection of email at rest. Moreover, every new Lacre enabled mail server increases security of end-to-end email encryption in transit. This is achieved by harnessing the power of PGP, which allows you to encrypt email between PGP users, so that messages will remain encrypted on their way from sender to recipient, without the need for Lacre to do anything. The role of Lacre in this case is merely to help popularize open encryption standards.
The goal of Lacre is to make itself obsolete! The more PGP becomes used on the internet, the less there is need for solutions like Lacre. If all email is end-to-end encrypted by default, using open interoperable standards, plain text emails should no longer have to be sent or stored on servers.
Lacre serves as a bridge between the current situation, where most of the email is transported and stored in plaintext, and a new situation where all emails are end-to-end encrypted using open standards.