Ephemeral keys

Receiving key
Ephemeral keys are generated during the process of notes encryption. The symmetric cipher algorithm (ChaCha20Poly1305) which applies to the memo block is required to use different keys for security reasons. They are derived from the random secret keys generated before the each encryption operation. The account's intermediate key is used for the derivation process.
  • The receiving key is a set of the intermediate key
    η\eta
    and ephemeral public key
    AiA_i
    . These are used to derive the note encryption key. Successfully decrypted notes with the
    η\eta
    key are considered received notes by a client.