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Message Encryption and Signature Overview

All messages get encrypted and digitally signed before the get sent over HTTP via TLS. A message consists therefore of a key info object, that contains the algorithm used and some other data necessary for decryption, and a number of cipher text objects for header, body and attachments. The following diagram shows how message parts are encrypted and decrypted.
Message Encryption Overview
Message Encryption Overview
  • HTTP Hyper Text Transfer Protocol
  • TLS Transport Layer Security