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blueprint-freespeech / ricochet-refresh

Anonymous peer-to-peer instant messaging
https://www.ricochetrefresh.net
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Use ECDH key agreement #5

Closed eleanor-em closed 3 years ago

eleanor-em commented 5 years ago

The current protocol uses RSA key exchange to establish a symmetric key. This is not the current industry standard as it does not provide perfect forward secrecy. The ideal option is to use ECDH key agreement.

odiferousmint commented 4 years ago

Worth noting:

[Note: The ED25519-V3 format is not the same as, e.g., SUPERCOP
  ed25519/ref, which stores the concatenation of the 32-byte ed25519
  hash seed concatenated with the 32-byte public key, and which derives
  the secret scalar and PRF secret by expanding the hash seed with
  SHA-512.  Our key blinding scheme is incompatible with storing
  private keys as seeds, so we store the secret scalar alongside the
  PRF secret, and just pay the cost of recomputing the public key when
  importing an ED25519-V3 key.]

Source: https://github.com/torproject/torspec/blob/master/control-spec.txt?ts=2#L1703

morganava commented 3 years ago

Fixed in alpha.