Added Threading

src/algo.rs

@@ -1,12 +1,15 @@
 // SPDX-License-Identifier: GPL-3.0-or-later
 use crate::{FBError, FBKey, FBObj, FBObjTrait, FieldOps, Packing};
 use crypto_bigint::{NonZero, RandomMod};
-use rand::{Rng, seq::IteratorRandom};
+use rand::{rngs::ThreadRng, seq::index, Rng};
+use rayon::iter::*;
+use std::marker::Send;
+use std::sync::RwLock;
 
 pub trait FBAlgo<T>
 where
-	Self: BlockOps<T>,
-	T: FieldOps + Packing + RandomMod,
+	Self: BlockOps<T> + Sync + Send,
+	T: FieldOps + Packing + RandomMod + Send + Sync,
 {
 	const MODULUS: NonZero<T>;
 
@@ -23,9 +26,10 @@ where
 		let r = (0..keybase_len)
 			.map(|_| T::random_mod(&mut rng, &Self::MODULUS))
 			.collect();
-		let c = (0..cipher_len)
+		let c_vec = (0..cipher_len)
 			.map(|_| T::random_mod(&mut rng, &Self::MODULUS))
 			.collect();
+		let c = RwLock::new(c_vec);
 
 		Ok(FBObj { c, r })
 	}
@@ -33,8 +37,11 @@ where
 	/// Adds the provided message to the ciphertext.
 	fn add(&mut self, msg: &[u8]) -> FBKey {
 		let indices = T::pack(msg)
-			.into_iter()
-			.map(|msg_uint| self.add_block(&msg_uint))
+			.into_par_iter()
+			.map_init(
+				|| rand::thread_rng(),
+				|rng, index_row| self.add_block(rng, &index_row),
+			)
 			.collect();
 
 		FBKey { indices }
@@ -44,8 +51,7 @@ where
 	/// # Errors
 	/// [InvalidKey](FBError::InvalidKey)
 	fn decrypt(&self, key: &FBKey) -> Result<Vec<u8>, FBError> {
-		let decr = key.indices
-			.iter()
+		let decr = key.indices.iter()
 			.map(|index_row| self.decrypt_block(&index_row))
 			.collect::<Result<Vec<_>, _>>()?;
 		let mut msg = T::unpack(decr)?;
@@ -55,40 +61,42 @@ where
 	}
 }
 
-
 pub trait BlockOps<T>
 where
 	Self: FBObjTrait<T>,
-	T: FieldOps + RandomMod,
+	T: FieldOps + RandomMod + Send + Sync,
 {
-	fn add_block(&mut self, msg_uint: &T) -> Vec<(usize, usize)> {
-		let c = self.cipher();
+	fn add_block(&self, rng: &mut ThreadRng, msg_uint: &T) -> Vec<(usize, usize)> {
 		let r = self.keybase();
-		let mut rng = rand::thread_rng();
 		let n = rng.gen_range(2..=r.len());
-		let mut c_i = (0..c.len()).choose_multiple(&mut rng, n-1);
-		let r_i = (0..r.len()).choose_multiple(&mut rng, n);
-		let mut sum = T::ZERO;
-		for (&ci, &ri) in c_i.iter().zip( r_i.iter() ) {
-			sum = sum.field_add( &c[ci].field_mul(&r[ri]) );
-		}
-		let ri_last = *r_i.last()
+		let r_i = index::sample(rng, r.len(), n);
+		let ri_last = r_i.iter().last()
 			.expect("r_i will contain at least 2 elements");
-		let mod_inv = r[ri_last].field_inv();
-		let c_new_el = msg_uint.field_sub(&sum)
-			.field_mul(&mod_inv);
-		let c = self.cipher_mut();
-		c.push(c_new_el);
-		c_i.push(c.len() - 1);
-		let indices = c_i.into_iter()
-			.zip(r_i.into_iter())
+		let ri_last_inv = r[ri_last].field_inv();
+		let c_i;
+		let c_len;
+		{
+			let mut c = self.cipher().write().unwrap();
+			c_i = index::sample(rng, c.len(), n - 1);
+			let sum = c_i.iter()
+				.zip(r_i.iter())
+				.map(|(ci, ri)| c[ci].field_mul(&r[ri]))
+				.reduce(|acc, i| acc.field_add(&i))
+				.unwrap();
+			let c_new_el = msg_uint.field_sub(&sum).field_mul(&ri_last_inv);
+			c.push(c_new_el);
+			c_len = c.len();
+		}
+		let indices = c_i.iter()
+			.chain([c_len - 1].into_iter())
+			.zip(r_i.iter())
 			.collect();
 
 		indices
 	}
 
 	fn decrypt_block(&self, indices: &[(usize, usize)]) -> Result<T, FBError> {
-		let (c, r) = (self.cipher(), self.keybase());
+		let (c, r) = (self.cipher().read().unwrap(), self.keybase());
 		if indices.len() > r.len() {
 			return Err(FBError::InvalidKey);
 		}
@@ -96,20 +104,20 @@ where
 		for &(ci, ri) in indices {
 			let c_el = c.get(ci).ok_or(FBError::InvalidKey)?;
 			let r_el = r.get(ri).ok_or(FBError::InvalidKey)?;
-			msg = msg.field_add( &c_el.field_mul(&r_el) );
+			msg = msg.field_add(&c_el.field_mul(&r_el));
 		}
 
 		Ok(msg)
 	}
 }
 
-
 #[test]
 fn encrypt_u128() {
 	use crypto_bigint::U128;
 	let msg = U128::from_u32(100);
-	let mut fb = FBObj::<U128>::init(18, 12).unwrap();
-	let key = fb.add_block(&msg);
+	let fb = FBObj::<U128>::init(18, 12).unwrap();
+	let rng = &mut rand::thread_rng();
+	let key = fb.add_block(rng, &msg);
 	let decrypted = fb.decrypt_block(&key).unwrap();
 	assert_eq!(msg, decrypted);
 }

src/encoding.rs

@@ -1,7 +1,8 @@
 // SPDX-License-Identifier: GPL-3.0-or-later
 use crate::{FBError, FBObj, FBObjTrait};
-use crypto_bigint::{ArrayEncoding, Bounded, generic_array::GenericArray};
 use base64::{prelude::BASE64_STANDARD, Engine};
+use crypto_bigint::{generic_array::GenericArray, ArrayEncoding, Bounded};
+use std::sync::RwLock;
 
 pub trait Encode<T>
 where
@@ -10,7 +11,8 @@ where
 {
 	/// Returns the byte representation of the ciphertext and keybase.
 	fn to_bytes(&self) -> (Vec<u8>, Vec<u8>) {
-		let c = self.cipher().iter()
+		let c = self.cipher().read().unwrap()
+			.iter()
 			.flat_map(|bigint| bigint.to_le_byte_array())
 			.collect();
 		let r = self.keybase().iter()
@@ -32,19 +34,17 @@ where
 	/// # Errors
 	/// - [InvalidParams](FBError::InvalidParams) - Are the parameters in the wrong order?
 	fn from_bytes(cipher: &[u8], keybase: &[u8]) -> Result<FBObj<T>, FBError> {
-		let chunk_to_uint = |chunk| {
-			T::from_le_byte_array(
-				GenericArray::clone_from_slice(chunk)
-			)};
-		let c: Vec<T> = cipher.chunks_exact(T::BYTES)
+		let chunk_to_uint = |chunk| T::from_le_byte_array(GenericArray::clone_from_slice(chunk));
+		let c_vec: Vec<T> = cipher.chunks_exact(T::BYTES)
 			.map(chunk_to_uint)
 			.collect();
 		let r: Vec<T> = keybase.chunks_exact(T::BYTES)
 			.map(chunk_to_uint)
 			.collect();
-		if r.len() > c.len() || r.len() < 2 {
+		if r.len() > c_vec.len() || r.len() < 2 {
 			return Err(FBError::InvalidParams);
 		}
+		let c = RwLock::new(c_vec);
 
 		Ok(FBObj {c, r})
 	}
@@ -54,7 +54,7 @@ where
 	/// # Errors
 	/// - [DecodeError](FBError::DecodeError)
 	/// - [InvalidParams](FBError::InvalidParams) - Are the parameters in the wrong order?
-	fn import(cipher: &str, keybase: &str) -> Result<FBObj<T>, FBError>	{
+	fn import(cipher: &str, keybase: &str) -> Result<FBObj<T>, FBError> {
 		let c_bytes = BASE64_STANDARD.decode(cipher)
 			.map_err(|_| FBError::DecodeError)?;
 		let r_bytes = BASE64_STANDARD.decode(keybase)

src/fbobj.rs

@@ -3,26 +3,24 @@ pub mod fb128;
 
 use crate::{BlockOps, Encode, FieldOps};
 use crypto_bigint::{ArrayEncoding, Bounded, RandomMod};
+use std::sync::RwLock;
+use std::marker::Sync;
 
 /// The False Bottom Object holds the ciphertext and the keybase. The provided type aliases can be used to pick a block size.
 pub struct FBObj<T> {
-	pub(crate) c: Vec<T>,
+	pub(crate) c: RwLock<Vec<T>>,
 	pub(crate) r: Vec<T>,
 }
 
 pub trait FBObjTrait<T> {
-	fn cipher(&self) -> &Vec<T>;
-	fn cipher_mut(&mut self) -> &mut Vec<T>;
+	fn cipher(&self) -> &RwLock<Vec<T>>;
 	fn keybase(&self) -> &Vec<T>;
 }
 
 impl<T> FBObjTrait<T> for FBObj<T> {
-	fn cipher(&self) -> &Vec<T> {
+	fn cipher(&self) -> &RwLock<Vec<T>> {
 		&self.c
 	}
-	fn cipher_mut(&mut self) -> &mut Vec<T> {
-		&mut self.c
-	}
 	fn keybase(&self) -> &Vec<T> {
 		&self.r
 	}
@@ -30,10 +28,10 @@ impl<T> FBObjTrait<T> for FBObj<T> {
 
 impl<T> BlockOps<T> for FBObj<T>
 where
-	T: FieldOps + RandomMod
+	T: FieldOps + RandomMod + Send + Sync
 {}
 
 impl<T> Encode<T> for FBObj<T>
 where
-	T: ArrayEncoding + Bounded,
+	T: ArrayEncoding + Bounded
 {}

src/fbobj/fb128.rs

@@ -24,7 +24,7 @@ impl FieldOps for U128 {
 		self.mul_mod_special(rhs, PRIME_POS)
 	}
 	fn field_inv(&self) -> Self {
-		self.inv_mod(&PRIME).0
+		self.inv_odd_mod(&PRIME).0
 	}
 }