42 lines
1.6 KiB
Markdown
42 lines
1.6 KiB
Markdown
# Terminology
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### _Broadcast channel_
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A secure broadcast channel in the context of multi-party computation protocols
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such as FROST has the following properties:
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1. Consistent. Each participant has the same view of the message sent over the channel.
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2. Authenticated. Players know that the message was in fact sent by the claimed sender. In practice, this
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requirement is often fulfilled by a PKI.
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3. Reliable Delivery. Player i knows that the message it sent was in fact received by the intended participants.
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4. Unordered. The channel does not guarantee ordering of messages.
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Possible deployment options:
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- Echo-broadcast (Goldwasser-Lindell)
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- Posting commitments to an authenticated centralized server that is trusted to
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provide a single view to all participants (also known as 'public bulletin board')
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### _Peer to peer channel_
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Peer-to-peer channels are authenticated, reliable, and unordered, per the
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definitions above. Additionally, peer-to-peer channels are _confidential_; i.e.,
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only participants `i` and `j` are allowed to know the contents of
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a message `msg_i,j`.
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Possible deployment options:
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- Mutually authenticated TLS
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- Wireguard
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### _Threshold secret sharing_
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Threshold secret sharing does not require a broadcast channel because the dealer is fully trusted.
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### _Verifiable secret sharing_
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Verifiable secret sharing requires a broadcast channel because the dealer is
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_not_ fully trusted: keygen participants verify the VSS commitment which is
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transmitted over the broadcast channel before accepting the shares distributed
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from the dealer, to ensure all participants have the same view of the commitment.
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