3 ms·

Wasn’t vanilla Diffie-Hellman designed for this exact yelling-in-a-crowded-room use case?

• fputz 6y ago
  A regular Diffie-Hellman key exchange is not authenticated, meaning that you don't know who you establish a key with. To authenticate this key exchange, you would need some prior security context (e.g., some shared secret or TLS certificates). In pairing scenarios, you often do not have a prior security context, since the goal is to establish one in the first place. Our approach works without a prior security context by using the physical signal propagation properties of the acoustic signals.
  • arianvanp 6y ago
    Doesn't 3DH solve this? E.g. what's used in signal?
    • fputz 6y ago
      No, because 3DH requires pre-exchanged public keys. For Signal, this key exchange might happen automatically, but you still need to manually compare the fingerprints to achieve authentication.