Fresh key shares for each connection
02A sender must not reuse its key share across multiple connections.
Related RFCs and changes
“Updates” changes part of an earlier RFC. “Obsoletes” replaces it. This list shows selected related documents.
DIAGRAM§ 4.3.8 ↗
RFC 9846 · § 4.3.8EXAMPLE
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03
Compatibility
Enforce freshness in your own sending behavior while accepting older compatible peers.
Protocol participantThreat or exceptionProtocol controlSimplified drawings · precise section references
RFC 8446 permitted reuseRFC 9846 § 4.3.8
The updated specification forbids senders from reusing key shares across connections, while requiring receivers to tolerate older peers that do.
Read the updated RFC section ↗Clients and servers must not reuse a key share between connections.
- Clients and servers must not reuse a key share between connections.
- For compatibility with RFC 8446 peers, receivers must still permit peer reuse.
- The rule concerns key-exchange shares; it is not a ban on reusable certificate keys.
The illustration is schematic. Example values are illustrative; profiles and later security guidance can add requirements.
Read the RFC section ↗Diagrams simplify the RFC. Read the linked sections for complete requirements.
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