Internet Assigned Numbers Authority

                                              TLS Encrypted Client Hello (ECH) Configuration Extensions

   Created
   2025-07-30

   Last Updated
   2025-07-30

   Available Formats
   [IMG]
   XML [IMG]
   HTML [IMG]
   Plain text

   Registry Included Below

     • TLS ECHConfig Extension

TLS ECHConfig Extension

   Registration Procedure(s)

 Specification Required

   Expert(s)

 Unassigned

   Reference
   [RFC-ietf-tls-esni-25]

   Note

 The role of the designated expert is described in [RFC8447].
 The designated expert [RFC8126] ensures that the specification is
 publicly available.  It is sufficient to have an Internet-Draft
 (that is posted and never published as an RFC) or a document from
 another standards body, industry consortium, university site, etc.
 The expert may provide more in-depth reviews, but their approval
 should not be taken as an endorsement of the extension.


   Available Formats
   [IMG]
   CSV

   Value  Extension Name Recommended       Reference             Notes
   0x0000 RESERVED       Y           [RFC-ietf-tls-esni-25] Grease entries.
   0x1A1A RESERVED       Y           [RFC-ietf-tls-esni-25] Grease entries.
   0x2A2A RESERVED       Y           [RFC-ietf-tls-esni-25] Grease entries.
   0x3A3A RESERVED       Y           [RFC-ietf-tls-esni-25] Grease entries.
   0x4A4A RESERVED       Y           [RFC-ietf-tls-esni-25] Grease entries.
   0x5A5A RESERVED       Y           [RFC-ietf-tls-esni-25] Grease entries.
   0x6A6A RESERVED       Y           [RFC-ietf-tls-esni-25] Grease entries.
   0x7A7A RESERVED       Y           [RFC-ietf-tls-esni-25] Grease entries.
   0x8A8A RESERVED       Y           [RFC-ietf-tls-esni-25] Grease entries.
   0x9A9A RESERVED       Y           [RFC-ietf-tls-esni-25] Grease entries.
   0xAAAA RESERVED       Y           [RFC-ietf-tls-esni-25] Grease entries.
   0xBABA RESERVED       Y           [RFC-ietf-tls-esni-25] Grease entries.
   0xCACA RESERVED       Y           [RFC-ietf-tls-esni-25] Grease entries.
   0xDADA RESERVED       Y           [RFC-ietf-tls-esni-25] Grease entries.
   0xEAEA RESERVED       Y           [RFC-ietf-tls-esni-25] Grease entries.
   0xFAFA RESERVED       Y           [RFC-ietf-tls-esni-25] Grease entries.

   Licensing Terms