Struct mc_oblivious_ram::PathORAM

pub struct PathORAM<ValueSize, Z, StorageType, RngType> where
    ValueSize: ArrayLength<u8> + PartialDiv<U8> + PartialDiv<U64>,
    Z: Unsigned + Mul<ValueSize> + Mul<U16>,
    RngType: RngCore + CryptoRng + Send + Sync + 'static,
    StorageType: ORAMStorage<Prod<Z, ValueSize>, Prod<Z, U16>> + Send + Sync + 'static,
    Prod<Z, ValueSize>: ArrayLength<u8> + PartialDiv<U8>,
    Prod<Z, U16>: ArrayLength<u8> + PartialDiv<U8>,  { /* fields omitted */ }

An implementation of PathORAM, using u64 to represent leaves in metadata.

Implementations

impl<ValueSize, Z, StorageType, RngType> PathORAM<ValueSize, Z, StorageType, RngType> where
    ValueSize: ArrayLength<u8> + PartialDiv<U8> + PartialDiv<U64>,
    Z: Unsigned + Mul<ValueSize> + Mul<U16>,
    RngType: RngCore + CryptoRng + Send + Sync + 'static,
    StorageType: ORAMStorage<Prod<Z, ValueSize>, Prod<Z, U16>> + Send + Sync + 'static,
    Prod<Z, ValueSize>: ArrayLength<u8> + PartialDiv<U8>,
    Prod<Z, U16>: ArrayLength<u8> + PartialDiv<U8>, 

pub fn new<PMC: PositionMapCreator<RngType>, SC: ORAMStorageCreator<Prod<Z, ValueSize>, Prod<Z, U16>, Output = StorageType>, F: FnMut() -> RngType + 'static>(
    size: u64,
    stash_size: usize,
    rng_maker: &mut F
) -> Self

New function creates this ORAM given a position map creator and a storage type creator and an Rng creator. The main thing that is going on here is, given the size, we are determining what the height will be, which will be like log(size) - log(bucket_size) Then we are making sure that all the various creators use this number.

Trait Implementations

impl<ValueSize, Z, StorageType, RngType> ORAM<ValueSize> for PathORAM<ValueSize, Z, StorageType, RngType> where
    ValueSize: ArrayLength<u8> + PartialDiv<U8> + PartialDiv<U64>,
    Z: Unsigned + Mul<ValueSize> + Mul<U16>,
    RngType: RngCore + CryptoRng + Send + Sync + 'static,
    StorageType: ORAMStorage<Prod<Z, ValueSize>, Prod<Z, U16>> + Send + Sync + 'static,
    Prod<Z, ValueSize>: ArrayLength<u8> + PartialDiv<U8>,
    Prod<Z, U16>: ArrayLength<u8> + PartialDiv<U8>, 

fn len(&self) -> u64

Get the number of values logically in the ORAM. This is also one more than the largest index that can be legally accessed.

fn access<T, F: FnOnce(&mut A64Bytes<ValueSize>) -> T>(
    &mut self,
    key: u64,
    f: F
) -> T

Access the ORAM at a position, calling a lambda with the recovered value, and returning the result of the lambda. This cannot fail, but will panic if index is out of bounds.

pub fn read(&mut self, index: u64) -> Aligned<A64, GenericArray<u8, ValueSize>>

High-level helper – when you only need to read and don’t need to write a new value, this is simpler than using access. In most ORAM there will not be a significantly faster implementation of this.

pub fn write(
    &mut self,
    index: u64,
    new_val: &Aligned<A64, GenericArray<u8, ValueSize>>
) -> Aligned<A64, GenericArray<u8, ValueSize>>

High-level helper – when you need to write a value and want the previous value, but you don’t need to see the previous value when deciding what to write, this is simpler than using access. In most ORAM there will not be a significantly faster implementation of this.