EncryptedMessage

DIDComm messaging

The encrypted form of a JWM is a JWE in General JSON Format.

• JWM - https://datatracker.ietf.org/doc/html/draft-looker-jwm-01
• DIDComm encrypted message - https://identity.foundation/didcomm-messaging/spec/#didcomm-encrypted-messages
• JWA - https://datatracker.ietf.org/doc/html/rfc7518

DIDComm messaging support only a subset of the supported algorithms of JWAs

Types:

• "authcrypt" - Authenticated Sender Encryption
  • ECDH-1PU MUST be used within the structure of a JWE. https://datatracker.ietf.org/doc/html/draft-madden-jose-ecdh-1pu-04
• "anoncrypt" - Anonymous Sender Encryption
  • ECDH-ES defined by RFC-7518 be used within the structure of a JWE. https://tools.ietf.org/html/rfc7518#section-4.6

Content Encryption Algorithms: (with a AES 256-bit keys, or with an optional implementation using XC20P algorithm) https://identity.foundation/didcomm-messaging/spec/#curves-and-content-encryption-algorithms

• X25519
• P-384
• P-256 (deprecated in favor of P-384)
• P-521 (Optional)

JWE protected header enc MUST be one of:

• A256CBC-HS512
• A256GCM
• XC20P (XChaCha20Poly1305 with a 256 bit key)

JWE protected header alg can be one of: https://identity.foundation/didcomm-messaging/spec/#key-wrapping-algorithms

• ECDH-ES+A256KW (with P-256; P-384; P-521; X25519) for "anoncrypt" messages
• ECDH-1PU+A256KW (with P-256; P-384; P-521; X25519) for "authcrypt" messages