Struct private_currency::crypto::SimpleRangeProof

pub struct SimpleRangeProof { /* fields omitted */ }

Range proof for a single value in the range [0; 1 << 64).

Theory

Bulletproofs provide an efficient scheme for proving that a committed value belongs to an interval. The scheme is non-interactive, succinct (i.e., the size of the data and the amount of computations necessary to verify the proof are small), and zero-knowledge (i.e., the verifier does not learn anything about the committed value besides the range).

Implementation details

We use the bulletproofs crate to implement proofs. The crate allows to efficiently prove several values at once, but this capability is not used as of now. Generators for proofs are initialized for a single party with Self::BITS range capacity.

Examples

let (commitment, opening) = Commitment::new(42_000_000);
// We need an opening to produce the proof
let proof = SimpleRangeProof::prove(&opening).unwrap();
// ...but don’t need one to verify it
assert!(proof.verify(&commitment));

Methods

impl SimpleRangeProof

pub const BITS: usize

Number of variable bits in the committed value: 64. The range to which the value must belong is [0, 1 << BITS).

pub fn prove(opening: &Opening) -> Option<Self>

Creates a proof for the specified value (which is provided together with the blinding factor as an Opening).

Return value

This method may fail along the lines of the underlying implementation. In this case, None is returned.

pub fn from_slice(slice: &[u8]) -> Option<Self>

Attempts to deserialize this proof from a byte slice.

pub fn verify(&self, commitment: &Commitment) -> bool

Verifies this proof with respect to the given committed value.

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

Serializes this proof into bytes.

Trait Implementations

impl Clone for SimpleRangeProof

fn clone(&self) -> SimpleRangeProof

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Debug for SimpleRangeProof

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

Formats the value using the given formatter.

impl ExonumJson for SimpleRangeProof

fn deserialize_field<B: WriteBufferWrapper>(     value: &Value,     buffer: &mut B,     from: u32,     to: u32 ) -> Result<(), Box<dyn Error>>

write deserialized field in buffer on place.

fn serialize_field(&self) -> Result<Value, Box<dyn Error + Send + Sync>>

serialize field as json::Value

impl<'a> SegmentField<'a> for SimpleRangeProof

fn item_size() -> u32

size of item fixed part that this Field collect.

fn count(&self) -> u32

count of items in collection

unsafe fn from_buffer(buffer: &'a [u8], from: u32, count: u32) -> Self

create collection from buffer

fn extend_buffer(&self, buffer: &mut Vec<u8>)

extend buffer with this collection

fn check_data(     buffer: &'a [u8],     from: CheckedOffset,     count: CheckedOffset,     latest_segment: CheckedOffset ) -> CheckResult

check collection data