P-256
Registry Context
P-256 is one of the initial entries in the JOSE JSON Web Key Elliptic Curve registry. It is a case-sensitive value used in the JWK `crv` parameter, and its initial registry entry has the JOSE Implementation Requirements value `Recommended+`.
Technical Summary
RFC 7518 defines `P-256` as a JWK `crv` value and registers it in the JSON Web Key Elliptic Curve registry. The registry records curve names, implementation requirements, and specification references.
When Used
Use when validating or documenting the EC JWK `crv` value `P-256` in JOSE implementations or registry data.
Normative Requirements
Registry registrants
RFC 7518 - Section 7.6.1
use a short curve name that does not exceed 8 characters without a compelling reason.
Condition: when requesting a curve name for the JSON Web Key Elliptic Curve registry
it is RECOMMENDED that the name be short -- not to exceed 8 characters without a compelling reason to do so.
Validation Guidance
Verify that this registry entry's curve name is exactly `P-256`; curve names are case sensitive.
Flag a requested curve name longer than 8 characters unless a compelling reason is documented.
Validate the JOSE Implementation Requirements field against `Required`, `Recommended`, `Optional`, `Deprecated`, or `Prohibited`, optionally followed by `+` or `-`.
Reject a requested curve name that case-insensitively matches another registered name unless the Designated Experts identify a compelling reason for an exception.
For a change to an implementation-requirements level, verify that the change follows the Specification Required policy, has Designated Expert review, and is defined by the new specification.
Security Notes
RFC 7518 - Section 6.2.1.1
SEC1 point compression is not supported for P-256, P-384, or P-521.
Reference
Details
- Entry Id
P-256- Curve Name
P-256- Curve Description
P-256 Curve- Jose Implementation Requirements
Recommended+- Change Controller
IESG- Reference
RFC7518 - Section 6.2.1.1