ot example

pop-mpc/examples/ot.rs

@@ -0,0 +1,64 @@
+// This example demonstrates how to securely and privately transfer data using OT extension.
+// In practical situations data would be communicated over a channel such as TCP.
+// For simplicity, this example shows how to use OT components in memory.
+
+use aes::cipher::{generic_array::GenericArray, NewBlockCipher};
+use aes::Aes128;
+use pop_mpc::block::Block;
+use pop_mpc::ot::{OTReceiver, OTSender};
+use rand::RngCore;
+use rand::SeedableRng;
+use rand_chacha::ChaCha12Rng;
+
+pub fn main() {
+    // Receiver choice bits
+    let choice = vec![false, true, false, false, true, true, false, true];
+
+    println!("Receiver chooses: {:?}", &choice);
+
+    // Sender messages the receiver chooses from
+    let inputs = [
+        [Block::new(0), Block::new(1)],
+        [Block::new(2), Block::new(3)],
+        [Block::new(4), Block::new(5)],
+        [Block::new(6), Block::new(7)],
+        [Block::new(8), Block::new(9)],
+        [Block::new(10), Block::new(11)],
+        [Block::new(12), Block::new(13)],
+        [Block::new(14), Block::new(15)],
+    ];
+
+    println!("Sender inputs: {:?}", &inputs);
+
+    // Setup RNGs and Ciphers for both sender and receiver
+    let s_rng = ChaCha12Rng::from_entropy();
+    let s_cipher = Aes128::new(GenericArray::from_slice(&[0u8; 16]));
+    let r_rng = ChaCha12Rng::from_entropy();
+    let r_cipher = Aes128::new(GenericArray::from_slice(&[0u8; 16]));
+
+    // First the receiver creates a setup message and passes it to sender
+    let mut receiver = OTReceiver::new(r_rng, r_cipher);
+    let base_sender_setup = receiver.base_setup();
+
+    // Sender takes receivers' setup and creates its own setup message
+    let mut sender = OTSender::new(s_rng, s_cipher, base_sender_setup);
+    let base_receiver_setup = sender.base_setup();
+
+    // Now the receiver generates some seeds from senders' setup and uses OT to transfer them
+    let send_seeds = receiver.base_send_seeds(base_receiver_setup);
+    sender.base_receive_seeds(send_seeds);
+
+    // Receiver generates OT extension setup and passes it to sender
+    let receiver_setup = receiver.extension_setup(&choice);
+
+    // Sender takes receivers' setup and runs its own extension setup
+    sender.extension_setup(receiver_setup);
+
+    // Finally, sender encrypts their inputs and sends them to receiver
+    let send = sender.send(&inputs);
+
+    // Receiver takes the encrypted inputs and is able to decrypt according to their choice bits
+    let receive = receiver.receive(&choice, send);
+
+    println!("Transferred messages: {:?}", receive.values);
+}

pop-mpc/src/lib.rs

@@ -10,3 +10,5 @@ pub mod garble;
 mod gate;
 pub mod ot;
 pub mod utils;
+
+pub use block::Block;

pop-mpc/src/ot/extension.rs

@@ -27,7 +27,7 @@ pub struct OTSender<R, C> {
 }
 
 pub struct OTSenderSend {
-    encrypted_values: Vec<[Block; 2]>,
+    pub encrypted_values: Vec<[Block; 2]>,
 }
 
 pub struct OTReceiver<R, C> {
@@ -44,7 +44,7 @@ pub struct OTReceiverSetup {
 }
 
 pub struct OTReceiverReceive {
-    values: Vec<Block>,
+    pub values: Vec<Block>,
 }
 
 impl<R: Rng + CryptoRng + SeedableRng, C: BlockCipher<BlockSize = U16> + BlockEncrypt>

pop-mpc/src/ot/mod.rs

@@ -1,2 +1,5 @@
 pub mod base;
 pub mod extension;
+
+pub use base::*;
+pub use extension::*;