3DES

The legacy content algorithm of AS2 envelopes, superseded by AES.

Definition

Triple DES applies the DES algorithm three times (encrypt-decrypt-encrypt) over 64-bit blocks. RFC 4130 required its support as the minimum AS2 content algorithm. NIST has deprecated it (SP 800-131A) and disallowed it after 2023; modern deployments replace it with AES-CBC or AES-GCM.

Origin

Specified by NIST in SP 800-67; its CMS use is defined by RFC 3370 (CMS Algorithms) and its historical AS2 mandate by RFC 4130, IETF EDIINT WG.

Example in context

contentEncryptionAlgorithm = des-ede3-cbc (1.2.840.113549.3.7) — still seen on older partner AS2 links not yet migrated to AES.

Related terms

• AES-128-CBC — the content algorithm that replaces 3DES.
• EnvelopedData — the structure where content encryption is applied.