Trait reef::traits::NullifierSet

source · 
pub trait NullifierSet: Clone + Debug + PartialEq + Serialize + DeserializeOwned + Send + Sync {
    type Proof: Clone + Debug + Send + Sync;

    // Required method
    fn multi_insert(
        &mut self,
        nullifiers: &[(Nullifier, Self::Proof)]
    ) -> Result<(), Self::Proof>;
}
Expand description

A set of nullifiers which have been spent.

In its simplest form this is just a set of nullifiers; however, notice that the only required interface is for inserting new nullifiers. Querying nullifiers is done on a network-specific basis, and we do not assume that the NullifierSet data structure will provide an interface for querying every nullifier that has been published. This could, for example, be implemented as a cryptographic commitment to a set of nullifiers, where multi_insert simply updates the commitment.

Since NullifierSet may be a commitment to a set that is actually represented elsewhere, it includes a notion of a Proof which can be used to authenticate that a particular nullifier is or isn’t in the set. All interfaces involving NullifierSet are written with the assumption that proofs are always necessary for inserting nullifiers, and must always be returned as authentication when querying nullifiers. An implementation of this trait which does not require authentication (for example, an implementation that maintains the entire nullifiers set in memory) may use trivial proofs, like ().

Required Associated Types§

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type Proof: Clone + Debug + Send + Sync

Authentication that a given nullifier is or isn’t in the set.

Required Methods§

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fn multi_insert( &mut self, nullifiers: &[(Nullifier, Self::Proof)] ) -> Result<(), Self::Proof>

Update the set to include additional nullifiers.

Insert a collection of nullifiers into the set given proofs that the nullifiers are not already in the set. If this function fails, it returns one of the input proofs which was invalid.

Implementors§