62 lines
1.3 KiB
Rust
62 lines
1.3 KiB
Rust
/*
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One-time encryption - keyspace of the OTE is also the range of the pseudo-random function
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*/
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use std::fmt;
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use bn::{Group, Fr, G1};
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use rand;
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pub struct OTMessage {
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pub m1: G1,
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pub m2: G1
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}
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pub struct OTCiphertext {
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c1: G1,
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c2: G1
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}
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pub fn keygen() -> G1 {
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let rng = &mut rand::thread_rng();
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let k = G1::random(rng);
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return k;
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}
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// encryption scheme can be implemented by encoding the plaintext as an element in a cyclic group G
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// and multiplying by a random group element.
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pub fn otenc(k: G1, m: &OTMessage) -> OTCiphertext {
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let c1 = k + m.m1;
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let c2 = k + m.m2;
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assert!(c1 != c2);
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return OTCiphertext { c1: c1, c2: c2 };
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}
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pub fn otdec(k: G1, c: &OTCiphertext) -> OTMessage {
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let x = c.c1 - k;
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let y = c.c2 - k;
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return OTMessage { m1: x, m2: y};
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}
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#[cfg(test)]
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mod tests {
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use super::*;
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use rand::{Rng, thread_rng};
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use bn::{G1, Group};
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#[test]
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#[ignore]
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fn one_time_enc_dec_works() {
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let rng = &mut rand::thread_rng();
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// Test the OTE scheme
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let k = keygen();
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let x = G1::random(rng);
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let y = G1::random(rng);
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let m = OTMessage { m1: x, m2: y };
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let c = otenc(k, &m);
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let orig_m = otdec(k, &c);
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assert!(m.m1 == orig_m.m1 && m.m2 == orig_m.m2);
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}
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}
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