HardFork3

core/src/consensus.rs

@@ -133,12 +133,18 @@ pub const FLOONET_FIRST_HARD_FORK: u64 = 185_040;
 /// Floonet second hard fork height, set to happen around 2019-12-19
 pub const FLOONET_SECOND_HARD_FORK: u64 = 298_080;
 
+/// Floonet second hard fork height, set to happen around 2020-06-20
+pub const FLOONET_THIRD_HARD_FORK: u64 = 552_960;
+
 /// AutomatedTesting and UserTesting first hard fork height.
 pub const TESTING_FIRST_HARD_FORK: u64 = 3;
 
 /// AutomatedTesting and UserTesting second hard fork height.
 pub const TESTING_SECOND_HARD_FORK: u64 = 6;
 
+/// AutomatedTesting and UserTesting third hard fork height.
+pub const TESTING_THIRD_HARD_FORK: u64 = 9;
+
 /// Compute possible block version at a given height, implements
 /// 6 months interval scheduled hard forks for the first 2 years.
 pub fn header_version(height: u64) -> HeaderVersion {
@@ -151,8 +157,10 @@ pub fn header_version(height: u64) -> HeaderVersion {
 				HeaderVersion(1)
 			} else if height < FLOONET_SECOND_HARD_FORK {
 				HeaderVersion(2)
-			} else if height < 3 * HARD_FORK_INTERVAL {
+			} else if height < FLOONET_THIRD_HARD_FORK {
 				HeaderVersion(3)
+			} else if height < 4 * HARD_FORK_INTERVAL {
+				HeaderVersion(4)
 			} else {
 				HeaderVersion(hf_interval)
 			}
@@ -162,8 +170,10 @@ pub fn header_version(height: u64) -> HeaderVersion {
 				HeaderVersion(1)
 			} else if height < TESTING_SECOND_HARD_FORK {
 				HeaderVersion(2)
-			} else if height < 3 * HARD_FORK_INTERVAL {
+			} else if height < TESTING_THIRD_HARD_FORK {
 				HeaderVersion(3)
+			} else if height < 4 * HARD_FORK_INTERVAL {
+				HeaderVersion(4)
 			} else {
 				HeaderVersion(hf_interval)
 			}
@@ -174,7 +184,7 @@ pub fn header_version(height: u64) -> HeaderVersion {
 /// Check whether the block version is valid at a given height, implements
 /// 6 months interval scheduled hard forks for the first 2 years.
 pub fn valid_header_version(height: u64, version: HeaderVersion) -> bool {
-	height < 3 * HARD_FORK_INTERVAL && version == header_version(height)
+	height < 4 * HARD_FORK_INTERVAL && version == header_version(height)
 }
 
 /// Number of blocks used to calculate difficulty adjustments
@@ -194,8 +204,7 @@ pub const DIFFICULTY_DAMP_FACTOR: u64 = 3;
 pub const AR_SCALE_DAMP_FACTOR: u64 = 13;
 
 /// Compute weight of a graph as number of siphash bits defining the graph
-/// Must be made dependent on height to phase out C31 in early 2020
-/// Later phase outs are on hold for now
+/// The height dependence allows a 30-week linear transition from C31+ to C32+ starting after 1 year
 pub fn graph_weight(height: u64, edge_bits: u8) -> u64 {
 	let mut xpr_edge_bits = edge_bits as u64;
 

core/src/global.rs

@@ -24,8 +24,8 @@ use crate::consensus::{
 };
 use crate::core::block::HeaderVersion;
 use crate::pow::{
-	self, new_cuckaroo_ctx, new_cuckarood_ctx, new_cuckaroom_ctx, new_cuckatoo_ctx, EdgeType,
-	PoWContext,
+	self, new_cuckaroo_ctx, new_cuckarood_ctx, new_cuckaroom_ctx, new_cuckarooz_ctx,
+	new_cuckatoo_ctx, EdgeType, PoWContext,
 };
 use std::cell::Cell;
 use util::OneTime;
@@ -187,8 +187,11 @@ where
 {
 	let chain_type = get_chain_type();
 	match chain_type {
-		// Mainnet has Cuckaroo(d)29 for AR and Cuckatoo31+ for AF
+		// Mainnet has Cuckaroo{,d,m,z}29 for AR and Cuckatoo31+ for AF
 		ChainTypes::Mainnet if edge_bits > 29 => new_cuckatoo_ctx(edge_bits, proof_size, max_sols),
+		ChainTypes::Mainnet if valid_header_version(height, HeaderVersion(4)) => {
+			new_cuckarooz_ctx(edge_bits, proof_size)
+		}
 		ChainTypes::Mainnet if valid_header_version(height, HeaderVersion(3)) => {
 			new_cuckaroom_ctx(edge_bits, proof_size)
 		}
@@ -199,6 +202,9 @@ where
 
 		// Same for Floonet
 		ChainTypes::Floonet if edge_bits > 29 => new_cuckatoo_ctx(edge_bits, proof_size, max_sols),
+		ChainTypes::Floonet if valid_header_version(height, HeaderVersion(4)) => {
+			new_cuckarooz_ctx(edge_bits, proof_size)
+		}
 		ChainTypes::Floonet if valid_header_version(height, HeaderVersion(3)) => {
 			new_cuckaroom_ctx(edge_bits, proof_size)
 		}

core/src/pow.rs

@@ -41,6 +41,7 @@ mod common;
 pub mod cuckaroo;
 pub mod cuckarood;
 pub mod cuckaroom;
+pub mod cuckarooz;
 pub mod cuckatoo;
 mod error;
 #[allow(dead_code)]
@@ -51,6 +52,7 @@ mod types;
 pub use crate::pow::cuckaroo::{new_cuckaroo_ctx, CuckarooContext};
 pub use crate::pow::cuckarood::{new_cuckarood_ctx, CuckaroodContext};
 pub use crate::pow::cuckaroom::{new_cuckaroom_ctx, CuckaroomContext};
+pub use crate::pow::cuckarooz::{new_cuckarooz_ctx, CuckaroozContext};
 pub use crate::pow::cuckatoo::{new_cuckatoo_ctx, CuckatooContext};
 pub use crate::pow::error::Error;
 use chrono::prelude::{DateTime, NaiveDateTime, Utc};

core/src/pow/cuckarooz.rs

@@ -0,0 +1,193 @@
+// Copyright 2020 The Grin Developers
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+//! Implementation of Cuckarooz Cycle, based on Cuckoo Cycle designed by
+//! John Tromp. Ported to Rust from https://github.com/tromp/cuckoo.
+//!
+//! Cuckarooz is a variation of Cuckaroo that's tweaked at the third HardFork
+//! to maintain ASIC-Resistance, as introduced in
+//! https://forum.grin.mw/t/introducing-the-final-tweak-cuckarooz
+//! It completes the choices of undirected vs directed edges and bipartite vs
+//! monopartite graphs, and is named after the last letter of the alphabet
+//! accordingly.
+
+use crate::global;
+use crate::pow::common::{CuckooParams, EdgeType};
+use crate::pow::error::{Error, ErrorKind};
+use crate::pow::siphash::siphash_block;
+use crate::pow::{PoWContext, Proof};
+
+/// Instantiate a new CuckaroozContext as a PowContext. Note that this can't
+/// be moved in the PoWContext trait as this particular trait needs to be
+/// convertible to an object trait.
+pub fn new_cuckarooz_ctx<T>(
+	edge_bits: u8,
+	proof_size: usize,
+) -> Result<Box<dyn PoWContext<T>>, Error>
+where
+	T: EdgeType + 'static,
+{
+	let params = CuckooParams::new(edge_bits, proof_size)?;
+	Ok(Box::new(CuckaroozContext { params }))
+}
+
+/// Cuckarooz cycle context. Only includes the verifier for now.
+pub struct CuckaroozContext<T>
+where
+	T: EdgeType,
+{
+	params: CuckooParams<T>,
+}
+
+impl<T> PoWContext<T> for CuckaroozContext<T>
+where
+	T: EdgeType,
+{
+	fn set_header_nonce(
+		&mut self,
+		header: Vec<u8>,
+		nonce: Option<u32>,
+		_solve: bool,
+	) -> Result<(), Error> {
+		self.params.reset_header_nonce(header, nonce)
+	}
+
+	fn find_cycles(&mut self) -> Result<Vec<Proof>, Error> {
+		unimplemented!()
+	}
+
+	fn verify(&self, proof: &Proof) -> Result<(), Error> {
+		if proof.proof_size() != global::proofsize() {
+			return Err(ErrorKind::Verification("wrong cycle length".to_owned()).into());
+		}
+		let nonces = &proof.nonces;
+		let mut uvs = vec![0u64; 2 * proof.proof_size()];
+		let mut xoruv: u64 = 0;
+
+		for n in 0..proof.proof_size() {
+			if nonces[n] > to_u64!(self.params.edge_mask) {
+				return Err(ErrorKind::Verification("edge too big".to_owned()).into());
+			}
+			if n > 0 && nonces[n] <= nonces[n - 1] {
+				return Err(ErrorKind::Verification("edges not ascending".to_owned()).into());
+			}
+			// 21 is standard siphash rotation constant
+			let edge = to_edge!(
+				T,
+				siphash_block(&self.params.siphash_keys, nonces[n], 21, true)
+			);
+			uvs[2 * n] = to_u64!(edge & self.params.edge_mask);
+			uvs[2 * n + 1] = to_u64!((edge >> 32) & self.params.edge_mask);
+			xoruv ^= uvs[2 * n] ^ uvs[2 * n + 1];
+		}
+		if xoruv != 0 {
+			return Err(ErrorKind::Verification("endpoints don't match up".to_owned()).into());
+		}
+		let mut n = 0;
+		let mut i = 0;
+		let mut j;
+		loop {
+			// follow cycle
+			j = i;
+			let mut k = j;
+			loop {
+				k = (k + 1) % (2 * self.params.proof_size);
+				if k == i {
+					break;
+				}
+				if uvs[k] == uvs[i] {
+					// find other edge endpoint matching one at i
+					if j != i {
+						return Err(ErrorKind::Verification("branch in cycle".to_owned()).into());
+					}
+					j = k;
+				}
+			}
+			if j == i {
+				return Err(ErrorKind::Verification("cycle dead ends".to_owned()).into());
+			}
+			i = j ^ 1;
+			n += 1;
+			if i == 0 {
+				break;
+			}
+		}
+		if n == self.params.proof_size {
+			Ok(())
+		} else {
+			Err(ErrorKind::Verification("cycle too short".to_owned()).into())
+		}
+	}
+}
+
+#[cfg(test)]
+mod test {
+	use super::*;
+
+	// empty header, nonce 71
+	static V1_19_HASH: [u64; 4] = [
+		0xd129f63fba4d9a85,
+		0x457dcb3666c5e09c,
+		0x045247a2e2ee75f7,
+		0x1a0f2e1bcb9d93ff,
+	];
+	static V1_19_SOL: [u64; 42] = [
+		0x33b6, 0x487b, 0x88b7, 0x10bf6, 0x15144, 0x17cb7, 0x22621, 0x2358e, 0x23775, 0x24fb3,
+		0x26b8a, 0x2876c, 0x2973e, 0x2f4ba, 0x30a62, 0x3a36b, 0x3ba5d, 0x3be67, 0x3ec56, 0x43141,
+		0x4b9c5, 0x4fa06, 0x51a5c, 0x523e5, 0x53d08, 0x57d34, 0x5c2de, 0x60bba, 0x62509, 0x64d69,
+		0x6803f, 0x68af4, 0x6bd52, 0x6f041, 0x6f900, 0x70051, 0x7097d, 0x735e8, 0x742c2, 0x79ae5,
+		0x7f64d, 0x7fd49,
+	];
+
+	// empty header, nonce 15
+	static V2_29_HASH: [u64; 4] = [
+		0x34bb4c75c929a2f5,
+		0x21df13263aa81235,
+		0x37d00939eae4be06,
+		0x473251cbf6941553,
+	];
+	static V2_29_SOL: [u64; 42] = [
+		0x49733a, 0x1d49107, 0x253d2ca, 0x5ad5e59, 0x5b671bd, 0x5dcae1c, 0x5f9a589, 0x65e9afc,
+		0x6a59a45, 0x7d9c6d3, 0x7df96e4, 0x8b26174, 0xa17b430, 0xa1c8c0d, 0xa8a0327, 0xabd7402,
+		0xacb7c77, 0xb67524f, 0xc1c15a6, 0xc7e2c26, 0xc7f5d8d, 0xcae478a, 0xdea9229, 0xe1ab49e,
+		0xf57c7db, 0xfb4e8c5, 0xff314aa, 0x110ccc12, 0x143e546f, 0x17007af8, 0x17140ea2,
+		0x173d7c5d, 0x175cd13f, 0x178b8880, 0x1801edc5, 0x18c8f56b, 0x18c8fe6d, 0x19f1a31a,
+		0x1bb028d1, 0x1caaa65a, 0x1cf29bc2, 0x1dbde27d,
+	];
+
+	#[test]
+	fn cuckarooz19_29_vectors() {
+		global::set_local_chain_type(global::ChainTypes::Mainnet);
+		let mut ctx19 = new_impl::<u64>(19, 42);
+		ctx19.params.siphash_keys = V1_19_HASH.clone();
+		assert!(ctx19
+			.verify(&Proof::new(V1_19_SOL.to_vec().clone()))
+			.is_ok());
+		assert!(ctx19.verify(&Proof::zero(42)).is_err());
+		let mut ctx29 = new_impl::<u64>(29, 42);
+		ctx29.params.siphash_keys = V2_29_HASH.clone();
+		assert!(ctx29
+			.verify(&Proof::new(V2_29_SOL.to_vec().clone()))
+			.is_ok());
+		assert!(ctx29.verify(&Proof::zero(42)).is_err());
+	}
+
+	fn new_impl<T>(edge_bits: u8, proof_size: usize) -> CuckaroozContext<T>
+	where
+		T: EdgeType,
+	{
+		let params = CuckooParams::new(edge_bits, proof_size).unwrap();
+		CuckaroozContext { params }
+	}
+}