ZK Rust Reference

Covering the types and functions available in ZkRust.

Types

Type	Comment
`bool`
`i8`
`i16`
`i32`
`u8`
`u16`
`u32`
`usize`
`Range`
`pbc_zk::Sbi1`	Secret-shared boolean.
`pbc_zk::Sbi8`	Secret-shared 8-bit signed integer.
`pbc_zk::Sbi16`	Secret-shared 16-bit signed integer.
`pbc_zk::Sbi32`	Secret-shared 32-bit signed integer.
`pbc_zk::Sbi64`	Secret-shared 64-bit signed integer.
`pbc_zk::Sbi128`	Secret-shared 128-bit signed integer.

Note that traits are not fully implemented, and these are mostly for illustrative purposes.

Trait	Documentation
`Public`	Public types are "normal" Rust types like `i32`, where the data is publicly known, for example because it is directly visible in the contract state.
`pbc_zk::Secret`	Secret types are types like `Sbi32` where the data is secret-shared between ZK nodes.
`pbc_zk::SecretBinary`	Sub-interface of `pbc_zk::Secret` where variables are secret-shared as bits.

Does not cover deprecated functions.

Function	Documentation
`pbc_zk::num_secret_variables() -> i32`	Determines the number of secret variables available to the computation. Variable ids are not contiguous and cannot by iterated over using `1..num_secret_variables()`
`pbc_zk::load_sbi<S: SecretBinary>(id: i32) -> S`	Loads the secret-shared data associated with variable `id` as the given type `S`.
`pbc_zk::load_metadata<P: Public>(id: i32) -> P`	Loads the public metadata associated with variable `id` as the given type `P`.
`pbc_zk::secret_variable_ids() -> Iterator<i32>`	Creates an iterator for secret variable ids.

These macros define what the MPC nodes should do when given the input.

Macro	Documentation
`zk_on_secret_input`	Declares an endpoint that the contract can be interacted with to add secret variables.
`zk_on_variable_inputted`	Declares an automatic hook for when a variable is confirmed inputted.
`zk_on_variable_rejected`	Declares an automatic hook for when a variable is rejected.
`zk_on_compute_complete`	Declares an automatic hook for when the zero-knowledge computation is finished.
`zk_on_variables_opened`	Declares an automatic hook for when secret variables is ready to be read..
`zk_on_attestation_complete`	Declares an automatic hook for when the contract have asked nodes to attest a piece of data,.