Struct mina_hasher::roinput::ROInput

pub struct ROInput { /* private fields */ }

Random oracle input structure

The random oracle input encapsulates the serialization format and methods using during hashing.

When implementing the Hashable trait to enable hashing for a type, you must implement its to_roinput() serialization method using the ROInput functions below.

The random oracle input structure is used (by generic code) to serialize the object into both a vector of pasta::Fp field elements and into a vector of bytes, depending on the situation.

Here is an example of how ROInput is used during the definition of the Hashable trait.

use mina_hasher::{Hashable, ROInput};
use mina_curves::pasta::Fp;

#[derive(Clone)]
pub struct MyExample {
    pub x: Fp,
    pub y: Fp,
    pub nonce: u64,
}

impl Hashable for MyExample {
    type D = ();

    fn to_roinput(&self) -> ROInput {
        ROInput::new()
            .append_field(self.x)
            .append_field(self.y)
            .append_u64(self.nonce)
    }

    fn domain_string(_: Self::D) -> Option<String> {
        format!("MyExampleMainnet").into()
    }
}

Details: For technical reasons related to our proof system and performance, non-field-element members are serialized for signing differently than other types. Additionally, during signing all members of the random oracle input get serialized together in two different ways: both as bytes and as a vector of field elements. The random oracle input automates and encapsulates this complexity.

Implementations

impl ROInput

pub fn new() -> Self

Create a new empty random oracle input

pub fn append_hashable(self, input: &impl Hashable) -> Self

Append a Hashable input

pub fn append_roinput(self, roi: ROInput) -> Self

Append another random oracle input

pub fn append_field(self, f: Fp) -> Self

Append a base field element

pub fn append_scalar(self, s: Fq) -> Self

Append a scalar field element

pub fn append_bool(self, b: bool) -> Self

Append a single bit

pub fn append_bytes(self, bytes: &[u8]) -> Self

Append bytes

pub fn append_u32(self, x: u32) -> Self

Append a 32-bit unsigned integer

pub fn append_u64(self, x: u64) -> Self

Append a 64-bit unsigned integer

pub fn to_bytes(&self) -> Vec<u8>

Serialize random oracle input to bytes

pub fn to_fields(&self) -> Vec<Fp>

Serialize random oracle input to vector of base field elements

Trait Implementations

impl Clone for ROInput

fn clone(&self) -> ROInput

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for ROInput

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Default for ROInput

fn default() -> ROInput

Returns the “default value” for a type.

impl PartialEq for ROInput

fn eq(&self, other: &ROInput) -> bool

This method tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

This method tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl Eq for ROInput

impl StructuralEq for ROInput

impl StructuralPartialEq for ROInput