Linked to security audit in POA wiki

README.md

@@ -14,7 +14,7 @@ decrypted and authenticated only with cooperation from at least `threshold +
 
 ## Security Audit
 
-An [official security audit](SECURITY_AUDIT.md) has been completed on `threshold_crypto` by [Jean-Philippe Aumasson](https://aumasson.jp/). No exploitable security issues were found, and potential improvements have been addressed. 
+An [official security audit](https://github.com/poanetwork/wiki/wiki/Threshold-Crypto-Audit) has been completed on `threshold_crypto` by [Jean-Philippe Aumasson](https://aumasson.jp/). No exploitable security issues were found, and potential improvements have been addressed. Outdated dependencies mentioned in the audit were updated in https://github.com/poanetwork/threshold_crypto/commit/54026f5fe7e0b5a52e446ac01a50469da1f15a71 with the exception of rand, which is currently pinned to version 0.4 (see https://github.com/poanetwork/hbbft/issues/145 for details).
 
 ## Usage
 
@@ -52,7 +52,7 @@ fn main() {
 
 ### Testing
 
-Run tests using the following command:
+Run tests with:
 
 ```
 $ cargo test
@@ -117,7 +117,7 @@ We use the [`criterion`](https://crates.io/crates/criterion) benchmarking librar
 
 ### Mock cryptography
 
-To speed up automatic tests of crates depending on `threshold_crypto`, the `use-insecure-test-only-mock-crypto` feature is available. **Activating this feature will effectively disable encryption and should only be used during tests!**. Essentially, the underlying elliptic curves will be replaced by small finite fields, yielding a 10-200X speed-up in execution. The resulting ciphers can be trivially broken in a number of ways and should never be used in production.
+To speed up automatic tests of crates depending on `threshold_crypto`, the `use-insecure-test-only-mock-crypto` feature is available. **Activating this feature will effectively disable encryption and should only be used during tests!** Essentially, the underlying elliptic curves will be replaced by small finite fields, yielding a 10-200X speed-up in execution. The resulting ciphers can be trivially broken in a number of ways and should never be used in production.
 
 ## License
 

SECURITY_AUDIT.md

@@ -1,91 +0,0 @@
-% POA Network threshold crypto audit
-% Jean-Philippe Aumasson
-% 20181024
-
-# Introduction
-
-We reviewed <https://github.com/poanetwork/threshold_crypto> for security defects (branch master, e28b77d).
-
-This implements the pairing-based threshold signature and encryption schemes, based on the [Boneh-Lynn-Shacham](https://www.iacr.org/archive/asiacrypt2001/22480516.pdf) pairing-based signature scheme, on its extension to threshold signatures using Lagrange interpolation by [Boldyreva](https://eprint.iacr.org/2002/118.pdf), and on the composition with an IND-CCA encryption construction as described by [Baek and Zheng](http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.119.1717&rep=rep1&type=pdf) (a.k.a. "signcryption").
-
-The elliptic-curve arithmetic and pairings are over the BLS12 elliptic curve, and is based on Sean Bowe's `pairing` crate (also used in Zcash), which we have audited in the past months.
-
-We reviewed the source code by manual inspection, and used modified versions of the unit tests in order to perform more testing of edge cases, malformed inputs, and so on. 
-We have checked the following points (non-exhaustive list):
-
-* Primitives (curve, hash) and their implementation
-* Use of rand? OsRng used for secret stuff
-* Exploitable panics
-* Unsafe unwraps
-* Memory zeroizing completeness
-* Equivalent keys using signed/unsigned indices
-* Leakage from ciphertext data structure
-* Incomplete/insufficient verification
-* Threshold enforcement and edge cases
-* Dependencies security/versions
-
-We did not find any exploitable security issue in the logic nor implementation of the threshold schemes, but only report potential improvements in the section Observations below.
-
-The audit work took approximately 6h30, including the review of
-literature related to the threshold cryptosystems implemented, and the
-review of patches following our initial observations.
-
-# Observations
-
-## Impossible error?
-
-```
-impl IntoFr for u64 {
-    fn into_fr(self) -> Fr {
-        Fr::from_repr(self.into()).expect("modulus is greater than u64::MAX")
-    }
-}
-```
-Can this really fail, since the trait is only defined for `u64` types, which cant be greater than `u64::MAX`?
-(We noticed this when trying to overflow the value / crash decryption.)
-
-### Status
-
-Failure is indeed impossible, but the `expect()` is meant as an
-clarification for the reader that the Result obtained must be less than
-`u64::MAX`.
-
-## Set a threshold threshold?
-
-Threshold value in SecretKeySet::random() is unlimited (but to `usize`), high values can panic,
-e.g. with `2^64-1` we get `thread 'tests::test_threshold_sig' panicked at 'capacity overflow', liballoc/raw_vec.rs:754:5`.
-
-Another panic occurs if calling `SecretKeySet::random(0, &mut rng);`.
-
-### Status
-
-The overflow was fixed, and we reviewed the patch.
-
-## Xored buffers length check
-
-The xor function does not check that input slices have an equal length, which is ok in the current context, since this function is always called with same-length slices.
-
-```
-fn xor_vec(x: &[u8], y: &[u8]) -> Vec<u8> {
-    x.iter().zip(y).map(|(a, b)| a ^ b).collect()
-}
-```
-
-### Status
-
-This was addressed by integrating this operation in the hashing logic.
-
-## Outdated dependencies
-
-* byteorder (1.2.3 instead of 1.2.6)
-* log (0.4.1 instead of 0.4.5)
-* rand (0.4.2 instead of 0.5.5); however note that 0.5 and above have made API changes breaking backward compatibility
-* rand_derive (0.3.1 instead of 0.5.0)
-* serde (1.0.55 instead of 1.0.79)
-* serde_derive (1.0.55 instead of 1.0.79)
-
-### Status
-
-The versions had not been updated at the time of our second review, but
-should be before the next release.
-