Ephemeral Key
Definition
An ephemeral key is a temporary cryptographic key generated for a single session or transaction, then securely discarded. Ephemeral keys enable forward secrecy: even if long-term keys are later compromised, past communications encrypted with deleted ephemeral keys remain secure.
Technical Explanation
In key exchange protocols like Diffie-Hellman, parties generate fresh ephemeral key pairs for each session. The shared secret derived from these temporary keys encrypts the session data. Once the session ends, ephemeral private keys are destroyed, making it impossible to recover the session key even with access to long-term credentials.
For post-quantum security, ephemeral keys must use quantum-resistant algorithms. Kyber-768 enables ephemeral key encapsulation where temporary public keys are exchanged, shared secrets are derived, and all ephemeral material is immediately deleted after use.
SynX Relevance
SynX uses ephemeral Kyber-768 keys for all wallet-to-daemon communications, providing quantum-safe forward secrecy. Each connection generates fresh key pairs, ensuring that historical network traffic cannot be decrypted even if future quantum computers crack long-term keys.
Frequently Asked Questions
- Where does SynX use ephemeral keys?
- In TLS-like session establishment between wallet and daemon, and in optional private transaction construction.
- How quickly are ephemeral keys deleted?
- Immediately after the session secret is derived—typically within milliseconds.
- Do ephemeral keys affect performance?
- Kyber operations are extremely fast, adding negligible latency to connections.
Quantum-safe forward secrecy for every connection. Discover SynX security