Replace our current PoW algorithm with oPoW

domain/consensus/utils/hashes/domains.go

@@ -13,6 +13,7 @@ const (
 	transcationSigningECDSADomain = "TransactionSigningHashECDSA"
 	blockDomain                   = "BlockHash"
 	proofOfWorkDomain             = "ProofOfWorkHash"
+	heavyHashDomain               = "HeavyHash"
 	merkleBranchDomain            = "MerkleBranchHash"
 )
 
@@ -73,6 +74,15 @@ func NewPoWHashWriter() HashWriter {
 	return HashWriter{blake}
 }
 
+// NewHeavyHashWriter Returns a new HashWriter used for the HeavyHash function
+func NewHeavyHashWriter() HashWriter {
+	blake, err := blake2b.New256([]byte(heavyHashDomain))
+	if err != nil {
+		panic(errors.Wrapf(err, "this should never happen. %s is less than 64 bytes", heavyHashDomain))
+	}
+	return HashWriter{blake}
+}
+
 // NewMerkleBranchHashWriter Returns a new HashWriter used for a merkle tree branch
 func NewMerkleBranchHashWriter() HashWriter {
 	blake, err := blake2b.New256([]byte(merkleBranchDomain))

domain/consensus/utils/pow/heavyhash.go

@@ -0,0 +1,91 @@
+package pow
+
+import (
+	"github.com/kaspanet/kaspad/domain/consensus/model/externalapi"
+	"github.com/kaspanet/kaspad/domain/consensus/utils/hashes"
+	"math"
+)
+
+const eps float64 = 1e-9
+
+type matrix [64][64]uint16
+
+func generateMatrix(hash *externalapi.DomainHash) *matrix {
+	var mat matrix
+	generator := newxoShiRo256PlusPlus(hash)
+	for {
+		for i := range mat {
+			for j := 0; j < 64; j += 16 {
+				val := generator.Uint64()
+				for shift := 0; shift < 16; shift++ {
+					mat[i][j+shift] = uint16(val >> (4 * shift) & 0x0F)
+				}
+			}
+		}
+		if mat.computeRank() == 64 {
+			return &mat
+		}
+	}
+}
+
+func (mat *matrix) computeRank() int {
+	var B [64][64]float64
+	for i := range B {
+		for j := range B[0] {
+			B[i][j] = float64(mat[i][j])
+		}
+	}
+	var rank int
+	var rowSelected [64]bool
+	for i := 0; i < 64; i++ {
+		var j int
+		for j := 0; j < 64; j++ {
+			if !rowSelected[j] && math.Abs(B[j][i]) > eps {
+				break
+			}
+		}
+		if j != 64 {
+			rank++
+			rowSelected[j] = true
+			for p := i + 1; p < 64; p++ {
+				B[j][p] /= B[j][i]
+			}
+			for k := 0; k < 64; k++ {
+				if k != j && math.Abs(B[k][i]) > eps {
+					for p := i + 1; p < 64; p++ {
+						B[k][p] -= B[j][p] * B[k][i]
+					}
+				}
+			}
+		}
+	}
+	return rank
+}
+
+func (mat *matrix) HeavyHash(hash *externalapi.DomainHash) *externalapi.DomainHash {
+	hashBytes := hash.ByteArray()
+	var vector [64]uint16
+	var product [64]uint16
+	for i := 0; i < 32; i++ {
+		vector[2*i] = uint16(hashBytes[i] >> 4)
+		vector[2*i+1] = uint16(hashBytes[i] & 0x0F)
+	}
+	// Matrix-vector multiplication, and convert to 4 bits.
+	for i := 0; i < 64; i++ {
+		var sum uint16
+		for j := 0; j < 64; j++ {
+			sum += mat[i][j] * vector[j]
+		}
+		product[i] = sum >> 10
+	}
+
+	// Concatenate 4 LSBs back to 8 bit xor with sum1
+	var res [32]byte
+	for i := range res {
+		res[i] = hashBytes[i] ^ (byte(product[2*i]<<4) | byte(product[2*i+1]))
+	}
+	// Hash again
+	writer := hashes.NewHeavyHashWriter()
+	writer.InfallibleWrite(res[:])
+	return writer.Finalize()
+}

domain/consensus/utils/pow/heavyhash_test.go

@@ -0,0 +1,92 @@
+package pow
+
+import (
+	"bytes"
+	"encoding/hex"
+	"github.com/kaspanet/kaspad/domain/consensus/utils/hashes"
+	"testing"
+)
+
+func TestMatrix_HeavyHash(t *testing.T) {
+	//expected, err := hex.DecodeString("39387f2e64e7c08d3ce0da8c491b4fcf2c862798dedb4690d819de7926aa4ecb") -> Keccak
+	expected, err := hex.DecodeString("137c69e3c4707cef02eeb8633d8a91fb5f62801342c9bc7e9514695c98e08b08")
+	if err != nil {
+		t.Fatal(err)
+	}
+	input := []byte{0xC1, 0xEC, 0xFD, 0xFC}
+	writer := hashes.NewPoWHashWriter()
+	writer.InfallibleWrite(input)
+	hashed := testMatrix.HeavyHash(writer.Finalize())
+
+	if !bytes.Equal(expected, hashed.ByteSlice()) {
+		t.Fatalf("expected: %x == %s", expected, hashed)
+	}
+
+}
+
+var testMatrix = matrix{
+	{13, 2, 14, 13, 2, 15, 14, 3, 10, 4, 1, 8, 4, 3, 8, 15, 15, 15, 15, 15, 2, 11, 15, 15, 15, 1, 7, 12, 12, 4, 2, 0, 6, 1, 14, 10, 12, 14, 15, 8, 10, 12, 0, 5, 13, 3, 14, 10, 10, 6, 12, 11, 11, 7, 6, 6, 10, 2, 2, 4, 11, 12, 0, 5},
+	{4, 13, 0, 2, 1, 15, 13, 13, 11, 2, 5, 12, 15, 7, 0, 10, 7, 2, 6, 3, 12, 0, 12, 0, 2, 6, 7, 7, 7, 7, 10, 12, 11, 14, 12, 12, 4, 11, 10, 0, 10, 11, 2, 10, 1, 7, 7, 12, 15, 9, 5, 14, 9, 12, 3, 0, 12, 13, 4, 13, 8, 15, 11, 6},
+	{14, 6, 15, 9, 8, 2, 2, 12, 2, 3, 4, 12, 13, 15, 4, 5, 13, 4, 3, 0, 14, 3, 5, 14, 3, 13, 4, 15, 9, 12, 7, 15, 5, 1, 13, 12, 9, 9, 8, 11, 14, 11, 4, 10, 12, 6, 12, 8, 6, 3, 9, 8, 1, 6, 0, 5, 8, 9, 12, 5, 14, 15, 2, 2},
+	{9, 6, 7, 6, 0, 11, 5, 6, 2, 14, 12, 6, 4, 13, 8, 9, 2, 1, 9, 7, 4, 5, 10, 8, 11, 11, 11, 15, 7, 11, 1, 14, 3, 8, 14, 8, 2, 8, 13, 7, 8, 8, 15, 7, 1, 13, 7, 9, 1, 7, 15, 15, 0, 0, 12, 15, 13, 5, 13, 10, 1, 5, 6, 13},
+	{4, 0, 12, 10, 6, 11, 14, 2, 2, 15, 4, 1, 2, 4, 2, 12, 13, 1, 9, 10, 8, 0, 2, 10, 13, 8, 9, 7, 5, 3, 8, 2, 6, 6, 1, 12, 3, 0, 1, 4, 2, 8, 3, 13, 6, 15, 0, 13, 14, 4, 15, 0, 7, 3, 7, 8, 5, 14, 14, 5, 5, 0, 1, 2},
+	{12, 14, 6, 3, 3, 4, 6, 7, 1, 3, 2, 7, 15, 15, 15, 10, 9, 12, 0, 6, 3, 8, 5, 0, 13, 5, 0, 6, 0, 14, 2, 12, 10, 4, 11, 2, 10, 7, 7, 6, 8, 11, 4, 4, 11, 9, 3, 12, 10, 5, 2, 6, 5, 5, 10, 13, 12, 10, 1, 6, 14, 7, 12, 4},
+	{7, 14, 6, 7, 7, 12, 4, 1, 8, 6, 8, 13, 13, 5, 12, 14, 10, 8, 6, 2, 12, 3, 8, 15, 5, 15, 15, 3, 14, 0, 8, 6, 9, 12, 9, 7, 3, 8, 4, 0, 7, 14, 3, 3, 13, 14, 3, 7, 3, 2, 2, 3, 3, 12, 6, 7, 4, 1, 14, 10, 6, 10, 2, 9},
+	{14, 11, 15, 5, 7, 10, 1, 11, 4, 2, 6, 2, 9, 7, 4, 0, 9, 12, 11, 2, 3, 13, 1, 5, 4, 10, 5, 6, 6, 12, 8, 1, 1, 15, 4, 2, 12, 12, 0, 4, 14, 3, 11, 1, 7, 5, 9, 4, 3, 15, 7, 3, 15, 9, 8, 3, 8, 3, 3, 6, 7, 6, 9, 2},
+	{10, 4, 6, 10, 5, 2, 15, 12, 0, 14, 14, 15, 14, 0, 12, 9, 1, 12, 4, 5, 5, 2, 10, 4, 2, 13, 11, 3, 1, 8, 10, 0, 7, 0, 12, 4, 11, 1, 14, 6, 14, 5, 5, 11, 11, 1, 3, 8, 0, 6, 11, 11, 8, 4, 7, 6, 14, 4, 9, 14, 9, 7, 13, 9},
+	{12, 7, 9, 8, 2, 3, 3, 5, 14, 8, 0, 9, 7, 4, 2, 15, 15, 3, 11, 11, 8, 5, 7, 5, 0, 15, 10, 8, 0, 13, 1, 14, 8, 10, 1, 4, 13, 1, 13, 3, 11, 11, 2, 3, 10, 6, 8, 14, 15, 2, 10, 10, 12, 7, 7, 6, 6, 3, 13, 8, 1, 14, 2, 1},
+	{2, 11, 6, 9, 13, 3, 12, 6, 0, 4, 6, 13, 8, 14, 6, 9, 10, 2, 10, 8, 4, 13, 6, 5, 0, 13, 15, 4, 2, 2, 1, 7, 5, 3, 3, 13, 7, 3, 5, 9, 15, 14, 14, 6, 0, 15, 11, 2, 4, 15, 6, 9, 8, 9, 15, 2, 6, 9, 15, 8, 4, 4, 11, 1},
+	{10, 11, 8, 3, 11, 13, 10, 2, 2, 5, 2, 14, 15, 10, 2, 11, 0, 1, 8, 2, 14, 1, 10, 0, 3, 7, 5, 10, 7, 8, 15, 7, 2, 5, 13, 4, 10, 3, 6, 2, 3, 9, 6, 11, 7, 14, 1, 11, 9, 3, 3, 7, 6, 0, 9, 11, 4, 10, 4, 1, 9, 7, 4, 15},
+	{13, 8, 15, 14, 11, 12, 5, 3, 9, 14, 1, 5, 14, 13, 14, 5, 13, 5, 4, 10, 9, 9, 0, 0, 6, 12, 5, 7, 2, 7, 2, 6, 6, 6, 1, 12, 9, 15, 7, 11, 11, 10, 11, 1, 10, 10, 0, 8, 1, 4, 5, 5, 8, 10, 10, 15, 6, 8, 13, 11, 11, 3, 15, 5},
+	{8, 11, 5, 10, 1, 10, 9, 1, 12, 7, 6, 11, 1, 1, 4, 1, 2, 8, 4, 4, 7, 7, 8, 2, 7, 1, 14, 1, 8, 15, 15, 12, 10, 4, 15, 11, 3, 6, 10, 7, 4, 0, 10, 9, 11, 7, 1, 14, 4, 14, 3, 14, 10, 4, 13, 12, 5, 3, 12, 7, 10, 8, 0, 3},
+	{9, 11, 6, 15, 14, 10, 0, 4, 7, 7, 6, 0, 7, 7, 12, 15, 5, 4, 12, 3, 7, 3, 0, 12, 2, 7, 11, 6, 7, 3, 2, 8, 5, 11, 9, 4, 3, 8, 11, 12, 3, 5, 14, 12, 4, 13, 12, 0, 3, 14, 4, 9, 1, 1, 9, 14, 10, 14, 8, 15, 6, 14, 10, 15},
+	{10, 14, 10, 0, 10, 12, 15, 0, 3, 9, 11, 10, 3, 5, 1, 1, 9, 1, 7, 15, 7, 8, 10, 10, 12, 11, 5, 1, 10, 3, 6, 6, 13, 0, 13, 1, 4, 5, 9, 4, 9, 15, 8, 4, 13, 13, 4, 5, 5, 11, 1, 13, 15, 3, 10, 15, 7, 11, 10, 15, 8, 12, 10, 3},
+	{8, 5, 11, 3, 8, 13, 15, 15, 3, 12, 1, 13, 1, 7, 1, 5, 6, 13, 7, 8, 5, 1, 12, 3, 10, 7, 12, 6, 14, 12, 15, 5, 3, 12, 2, 15, 11, 13, 1, 13, 8, 5, 8, 0, 13, 15, 7, 13, 6, 13, 10, 1, 11, 0, 8, 9, 5, 11, 2, 9, 9, 10, 4, 15},
+	{0, 4, 12, 14, 3, 1, 7, 5, 11, 13, 5, 3, 11, 12, 6, 8, 10, 15, 11, 8, 7, 10, 0, 2, 5, 15, 6, 10, 4, 2, 3, 1, 13, 7, 6, 12, 14, 7, 6, 14, 12, 10, 6, 14, 12, 0, 12, 11, 6, 9, 3, 1, 12, 15, 15, 3, 5, 5, 10, 11, 7, 15, 13, 3},
+	{12, 14, 2, 14, 13, 6, 15, 7, 8, 8, 14, 13, 9, 2, 2, 10, 3, 15, 6, 10, 11, 7, 13, 0, 12, 1, 5, 8, 8, 12, 1, 11, 1, 3, 2, 4, 10, 7, 7, 7, 3, 10, 7, 2, 2, 3, 0, 1, 13, 5, 8, 2, 14, 0, 11, 13, 9, 3, 13, 2, 14, 2, 15, 4},
+	{0, 0, 13, 6, 9, 12, 15, 7, 8, 0, 7, 4, 12, 15, 3, 2, 7, 1, 14, 4, 9, 3, 13, 12, 11, 12, 9, 9, 3, 7, 10, 9, 1, 9, 10, 2, 10, 14, 11, 0, 14, 4, 15, 12, 12, 9, 9, 8, 14, 1, 9, 14, 0, 6, 1, 0, 13, 9, 7, 6, 13, 2, 3, 9},
+	{8, 0, 10, 13, 0, 7, 9, 7, 5, 1, 0, 3, 7, 10, 3, 15, 1, 15, 3, 11, 2, 6, 3, 10, 0, 10, 10, 3, 4, 15, 8, 6, 11, 11, 7, 5, 8, 5, 7, 15, 1, 11, 7, 13, 13, 6, 13, 13, 4, 2, 3, 15, 9, 5, 10, 6, 6, 6, 3, 11, 15, 13, 1, 15},
+	{1, 1, 2, 10, 2, 2, 9, 5, 9, 2, 0, 1, 14, 2, 11, 6, 11, 6, 1, 0, 13, 7, 14, 1, 15, 14, 13, 7, 12, 11, 8, 11, 2, 11, 6, 10, 2, 3, 0, 0, 15, 0, 4, 6, 4, 12, 5, 5, 7, 14, 10, 6, 0, 3, 13, 0, 8, 1, 13, 10, 5, 1, 7, 5},
+	{0, 5, 2, 12, 10, 2, 5, 1, 14, 0, 1, 4, 15, 11, 8, 7, 11, 14, 15, 6, 4, 1, 6, 6, 7, 13, 12, 5, 13, 2, 1, 6, 2, 13, 5, 15, 0, 8, 8, 6, 5, 5, 2, 0, 3, 13, 14, 2, 10, 5, 7, 6, 14, 5, 1, 4, 11, 2, 11, 1, 8, 15, 2, 4},
+	{9, 9, 4, 5, 2, 5, 3, 12, 14, 5, 1, 3, 3, 0, 0, 6, 7, 14, 0, 15, 14, 11, 3, 10, 1, 9, 4, 14, 7, 14, 1, 0, 15, 11, 5, 9, 4, 0, 0, 10, 4, 4, 0, 7, 8, 15, 12, 8, 10, 8, 1, 2, 1, 11, 12, 14, 14, 14, 8, 10, 1, 5, 13, 10},
+	{5, 10, 4, 4, 11, 10, 0, 6, 0, 12, 10, 5, 9, 11, 8, 10, 11, 3, 11, 14, 12, 9, 4, 6, 11, 12, 8, 7, 6, 14, 0, 6, 12, 4, 5, 3, 9, 0, 11, 6, 1, 3, 2, 12, 8, 9, 7, 12, 14, 7, 12, 6, 11, 13, 0, 2, 1, 3, 1, 8, 12, 2, 15, 15},
+	{10, 11, 2, 3, 11, 10, 1, 7, 1, 10, 10, 14, 5, 13, 10, 3, 11, 15, 9, 14, 11, 11, 3, 15, 11, 6, 15, 13, 13, 1, 1, 10, 5, 1, 5, 11, 10, 3, 9, 12, 12, 1, 5, 6, 3, 3, 1, 1, 12, 8, 3, 15, 6, 2, 8, 14, 3, 4, 10, 9, 7, 13, 2, 6},
+	{12, 0, 1, 0, 4, 3, 3, 6, 8, 3, 1, 13, 6, 12, 1, 1, 1, 4, 12, 4, 4, 9, 9, 14, 15, 3, 6, 4, 11, 1, 12, 5, 6, 0, 10, 9, 1, 8, 14, 5, 2, 8, 4, 15, 12, 13, 7, 14, 12, 2, 6, 9, 4, 13, 0, 15, 10, 10, 6, 12, 7, 12, 9, 10},
+	{0, 8, 5, 11, 12, 12, 11, 7, 2, 9, 2, 15, 1, 1, 0, 0, 6, 5, 10, 1, 11, 12, 8, 7, 1, 7, 10, 4, 2, 8, 2, 5, 1, 1, 2, 9, 2, 0, 3, 7, 5, 1, 5, 5, 3, 1, 4, 3, 14, 8, 11, 7, 8, 0, 2, 13, 3, 15, 1, 13, 14, 15, 11, 13},
+	{8, 13, 5, 14, 2, 9, 9, 13, 15, 8, 2, 14, 4, 2, 6, 0, 1, 13, 10, 13, 6, 12, 15, 11, 6, 11, 9, 9, 2, 9, 6, 14, 2, 9, 12, 1, 13, 9, 5, 11, 10, 4, 4, 5, 8, 9, 13, 10, 9, 0, 5, 15, 4, 12, 7, 10, 6, 5, 5, 15, 8, 8, 11, 14},
+	{6, 9, 6, 7, 1, 15, 0, 1, 4, 15, 5, 3, 10, 9, 15, 9, 14, 12, 7, 6, 3, 0, 12, 8, 12, 2, 11, 8, 11, 8, 1, 10, 10, 7, 7, 5, 3, 5, 1, 2, 13, 11, 2, 5, 2, 10, 10, 1, 14, 14, 8, 1, 11, 1, 2, 6, 15, 10, 8, 7, 10, 7, 0, 3},
+	{12, 6, 11, 1, 1, 7, 8, 1, 5, 5, 8, 4, 6, 5, 6, 4, 2, 8, 4, 1, 0, 0, 14, 2, 10, 14, 14, 11, 2, 9, 14, 15, 12, 14, 9, 3, 7, 14, 4, 7, 12, 9, 3, 5, 1, 0, 12, 9, 10, 5, 11, 12, 10, 10, 6, 14, 6, 13, 13, 5, 5, 10, 13, 10},
+	{12, 6, 13, 0, 8, 0, 10, 6, 15, 15, 7, 3, 0, 10, 13, 14, 10, 13, 5, 13, 15, 14, 3, 4, 10, 10, 9, 6, 6, 15, 2, 7, 0, 10, 6, 14, 2, 9, 11, 7, 5, 5, 13, 14, 11, 15, 9, 4, 2, 0, 15, 5, 4, 14, 14, 1, 3, 4, 5, 8, 1, 1, 10, 12},
+	{2, 5, 0, 4, 11, 5, 5, 6, 10, 4, 6, 7, 10, 3, 0, 14, 14, 0, 12, 15, 11, 12, 13, 7, 6, 3, 9, 1, 9, 8, 8, 8, 4, 10, 3, 1, 7, 10, 3, 2, 12, 6, 15, 14, 0, 6, 8, 10, 1, 9, 12, 12, 15, 7, 1, 11, 15, 13, 0, 4, 10, 0, 12, 11},
+	{8, 12, 14, 15, 14, 15, 10, 0, 2, 14, 3, 1, 2, 6, 0, 2, 1, 7, 9, 0, 15, 13, 5, 14, 6, 8, 15, 4, 15, 6, 10, 6, 15, 3, 12, 8, 5, 4, 10, 5, 3, 0, 4, 13, 10, 9, 8, 4, 6, 3, 9, 6, 12, 11, 9, 13, 8, 10, 9, 9, 8, 12, 1, 2},
+	{11, 10, 15, 15, 5, 14, 15, 7, 5, 9, 14, 14, 7, 11, 6, 6, 3, 8, 2, 3, 4, 14, 11, 1, 12, 15, 11, 6, 0, 0, 13, 7, 14, 3, 12, 14, 0, 15, 6, 1, 11, 2, 11, 8, 3, 13, 4, 12, 10, 13, 7, 14, 9, 13, 3, 10, 2, 14, 13, 4, 12, 13, 14, 10},
+	{1, 11, 2, 12, 1, 10, 7, 12, 3, 3, 14, 9, 1, 10, 0, 11, 8, 10, 12, 12, 4, 12, 2, 11, 5, 0, 3, 15, 8, 2, 14, 3, 10, 2, 1, 13, 6, 14, 0, 0, 8, 11, 6, 13, 15, 10, 12, 7, 7, 11, 14, 9, 2, 7, 6, 8, 14, 9, 14, 10, 11, 9, 9, 12},
+	{5, 10, 14, 2, 1, 4, 11, 5, 10, 2, 13, 9, 6, 12, 11, 5, 13, 4, 5, 14, 8, 7, 15, 9, 8, 4, 5, 2, 9, 11, 5, 3, 12, 2, 6, 1, 7, 4, 11, 4, 15, 0, 5, 2, 13, 11, 11, 2, 15, 10, 0, 12, 5, 8, 10, 1, 4, 11, 3, 13, 11, 7, 9, 14},
+	{9, 8, 10, 5, 0, 2, 5, 8, 7, 3, 3, 6, 11, 1, 13, 15, 4, 4, 11, 6, 2, 6, 13, 11, 2, 6, 9, 4, 5, 13, 12, 2, 8, 7, 7, 12, 14, 15, 5, 12, 7, 0, 15, 15, 0, 5, 15, 0, 3, 9, 10, 15, 9, 11, 10, 10, 5, 3, 9, 3, 12, 13, 0, 13},
+	{1, 11, 15, 0, 10, 5, 3, 5, 6, 7, 1, 11, 4, 11, 4, 2, 5, 12, 2, 5, 5, 6, 1, 5, 14, 9, 1, 5, 14, 12, 6, 10, 0, 8, 5, 11, 11, 11, 12, 10, 8, 10, 10, 1, 14, 1, 0, 8, 4, 7, 0, 11, 3, 1, 11, 12, 11, 8, 14, 15, 9, 3, 1, 14},
+	{14, 11, 12, 12, 4, 6, 8, 14, 15, 1, 11, 2, 13, 3, 6, 2, 7, 1, 8, 1, 4, 9, 11, 15, 8, 1, 10, 13, 4, 13, 2, 7, 7, 10, 5, 2, 12, 12, 12, 3, 10, 8, 2, 11, 0, 3, 8, 9, 4, 2, 15, 7, 15, 6, 4, 6, 12, 7, 14, 9, 9, 8, 14, 12},
+	{15, 4, 8, 12, 11, 11, 9, 5, 0, 0, 7, 6, 10, 5, 8, 2, 5, 6, 14, 11, 13, 0, 13, 15, 5, 4, 9, 15, 13, 12, 14, 15, 10, 2, 3, 6, 10, 14, 1, 8, 6, 7, 10, 1, 14, 9, 12, 13, 7, 2, 12, 10, 6, 11, 15, 1, 15, 11, 13, 0, 6, 13, 7, 15},
+	{3, 3, 12, 5, 14, 9, 14, 14, 8, 0, 9, 1, 2, 2, 14, 11, 7, 1, 3, 1, 14, 15, 12, 8, 14, 2, 4, 13, 10, 5, 10, 8, 1, 7, 6, 5, 4, 2, 11, 5, 4, 13, 14, 6, 13, 15, 6, 6, 7, 12, 11, 5, 13, 10, 9, 13, 9, 14, 5, 6, 7, 14, 11, 7},
+	{14, 12, 11, 5, 0, 5, 10, 5, 7, 1, 7, 11, 1, 0, 13, 6, 5, 14, 3, 0, 5, 14, 6, 7, 8, 5, 8, 6, 6, 3, 6, 1, 8, 3, 10, 7, 15, 6, 11, 6, 6, 7, 13, 2, 2, 0, 0, 11, 1, 15, 2, 14, 5, 1, 4, 8, 0, 1, 8, 0, 1, 1, 2, 2},
+	{10, 13, 13, 3, 15, 14, 9, 12, 15, 15, 8, 5, 8, 10, 5, 9, 6, 6, 7, 15, 1, 0, 14, 9, 1, 11, 6, 11, 13, 4, 6, 14, 9, 12, 13, 8, 14, 6, 14, 2, 3, 15, 4, 4, 14, 4, 9, 12, 8, 0, 9, 11, 13, 10, 8, 14, 3, 5, 7, 11, 6, 7, 15, 2},
+	{9, 9, 11, 6, 11, 0, 5, 4, 8, 10, 8, 11, 2, 12, 8, 7, 11, 13, 6, 1, 13, 13, 11, 4, 5, 7, 7, 9, 6, 4, 12, 0, 11, 8, 6, 12, 11, 4, 15, 11, 12, 8, 11, 11, 1, 3, 6, 14, 9, 6, 7, 5, 0, 10, 3, 15, 13, 7, 0, 1, 13, 15, 1, 14},
+	{10, 6, 8, 7, 3, 6, 9, 15, 1, 3, 10, 14, 9, 0, 0, 10, 0, 15, 2, 0, 0, 0, 6, 0, 13, 9, 9, 1, 8, 6, 13, 2, 1, 9, 14, 9, 1, 4, 8, 4, 2, 0, 8, 5, 0, 11, 12, 15, 13, 1, 14, 14, 15, 7, 8, 4, 4, 12, 1, 12, 8, 3, 9, 5},
+	{12, 11, 1, 4, 10, 14, 8, 12, 2, 4, 15, 2, 9, 7, 7, 11, 15, 12, 10, 11, 7, 4, 13, 0, 8, 6, 8, 8, 10, 5, 5, 13, 3, 7, 9, 13, 13, 14, 6, 8, 1, 5, 7, 12, 4, 4, 6, 9, 13, 1, 6, 1, 6, 14, 5, 8, 2, 10, 4, 10, 1, 9, 6, 15},
+	{4, 13, 4, 9, 6, 11, 1, 8, 7, 11, 11, 1, 3, 10, 12, 11, 1, 10, 6, 10, 0, 7, 3, 0, 0, 6, 3, 9, 2, 1, 4, 8, 2, 10, 2, 15, 9, 15, 14, 14, 15, 14, 3, 2, 7, 6, 6, 10, 8, 8, 4, 11, 1, 13, 6, 0, 2, 10, 0, 11, 15, 14, 6, 9},
+	{15, 0, 12, 13, 0, 9, 10, 4, 11, 5, 10, 0, 8, 7, 3, 2, 12, 6, 3, 8, 5, 15, 14, 2, 13, 13, 6, 11, 5, 6, 9, 10, 14, 5, 14, 4, 9, 7, 5, 11, 13, 2, 7, 1, 14, 9, 0, 7, 8, 12, 11, 15, 2, 1, 5, 11, 3, 7, 5, 1, 6, 3, 8, 6},
+	{0, 3, 8, 1, 4, 6, 3, 1, 3, 8, 2, 0, 15, 15, 14, 15, 13, 10, 11, 9, 2, 11, 5, 12, 3, 3, 0, 1, 5, 3, 11, 6, 10, 11, 8, 5, 7, 15, 4, 12, 8, 8, 12, 12, 12, 1, 9, 4, 11, 6, 10, 11, 1, 12, 8, 12, 5, 6, 1, 14, 2, 10, 3, 0},
+	{10, 13, 6, 9, 11, 1, 4, 10, 0, 13, 8, 7, 4, 12, 15, 5, 14, 12, 6, 9, 0, 0, 10, 5, 13, 10, 15, 3, 0, 8, 7, 0, 9, 8, 10, 6, 11, 8, 10, 13, 11, 7, 5, 5, 9, 13, 1, 15, 0, 5, 15, 5, 4, 7, 9, 9, 15, 8, 2, 6, 3, 8, 5, 8},
+	{14, 0, 6, 2, 4, 12, 2, 13, 6, 10, 5, 2, 2, 1, 6, 11, 1, 6, 9, 13, 0, 13, 9, 3, 12, 4, 3, 8, 7, 0, 9, 12, 0, 1, 7, 10, 10, 7, 3, 9, 13, 5, 15, 4, 13, 0, 8, 5, 4, 14, 11, 3, 3, 13, 15, 9, 9, 12, 9, 5, 2, 0, 1, 14},
+	{4, 14, 13, 0, 14, 15, 11, 10, 11, 1, 3, 3, 9, 1, 12, 8, 6, 5, 15, 11, 1, 7, 5, 3, 8, 13, 0, 13, 11, 5, 8, 1, 8, 6, 13, 4, 13, 7, 12, 6, 5, 5, 7, 0, 12, 1, 1, 8, 1, 6, 4, 2, 8, 8, 15, 11, 11, 11, 4, 4, 4, 7, 13, 12},
+	{14, 15, 10, 0, 4, 3, 1, 9, 13, 7, 9, 9, 15, 5, 0, 3, 9, 6, 4, 7, 13, 11, 3, 2, 7, 1, 6, 8, 13, 7, 10, 4, 3, 9, 5, 9, 2, 6, 10, 7, 9, 13, 2, 14, 2, 14, 7, 2, 14, 2, 8, 8, 0, 9, 0, 9, 12, 6, 7, 7, 6, 8, 12, 13},
+	{5, 15, 8, 12, 11, 3, 13, 4, 5, 14, 10, 4, 15, 15, 1, 10, 9, 14, 6, 6, 4, 12, 4, 9, 12, 2, 15, 13, 2, 5, 12, 2, 3, 2, 15, 11, 12, 2, 6, 2, 11, 6, 7, 9, 12, 10, 5, 1, 1, 5, 9, 6, 14, 11, 3, 11, 6, 10, 11, 11, 0, 12, 15, 1},
+	{12, 6, 8, 10, 2, 5, 7, 9, 8, 14, 15, 15, 13, 10, 15, 3, 10, 10, 6, 10, 14, 10, 7, 5, 3, 7, 6, 12, 11, 12, 8, 9, 12, 9, 15, 15, 15, 7, 8, 3, 15, 14, 1, 12, 0, 0, 4, 0, 9, 10, 8, 7, 14, 10, 8, 14, 6, 2, 8, 1, 11, 10, 0, 1},
+	{12, 1, 2, 12, 7, 10, 4, 11, 5, 14, 10, 2, 2, 9, 4, 13, 3, 14, 3, 15, 5, 0, 14, 7, 7, 15, 6, 5, 2, 8, 15, 9, 6, 6, 13, 10, 9, 8, 6, 3, 14, 7, 12, 9, 7, 8, 13, 12, 14, 13, 6, 0, 5, 1, 9, 12, 14, 0, 11, 11, 6, 3, 11, 7},
+	{15, 4, 8, 12, 8, 11, 4, 15, 1, 6, 2, 13, 1, 7, 7, 12, 0, 8, 14, 14, 10, 14, 0, 12, 0, 3, 3, 11, 7, 4, 2, 13, 0, 0, 11, 2, 5, 8, 12, 11, 6, 5, 6, 0, 0, 4, 0, 0, 1, 9, 9, 11, 3, 2, 13, 4, 13, 9, 15, 4, 7, 8, 3, 2},
+	{3, 13, 8, 8, 12, 10, 5, 4, 7, 13, 10, 13, 14, 3, 2, 12, 11, 0, 9, 5, 6, 4, 14, 4, 6, 9, 2, 5, 10, 3, 9, 10, 5, 0, 12, 5, 15, 5, 15, 15, 2, 12, 3, 11, 0, 15, 9, 14, 1, 5, 6, 6, 14, 5, 8, 0, 5, 9, 3, 7, 7, 12, 15, 1},
+	{1, 11, 7, 4, 13, 3, 0, 8, 11, 9, 15, 1, 4, 12, 2, 12, 10, 4, 14, 3, 9, 14, 14, 2, 3, 11, 12, 4, 5, 10, 6, 15, 2, 13, 13, 9, 9, 1, 11, 12, 12, 14, 1, 5, 15, 1, 7, 14, 12, 10, 11, 13, 13, 5, 2, 4, 7, 7, 9, 4, 14, 15, 13, 10},
+	{14, 15, 9, 14, 9, 5, 13, 2, 0, 0, 14, 8, 6, 2, 0, 7, 11, 10, 2, 13, 2, 14, 9, 6, 4, 11, 5, 14, 6, 1, 6, 14, 6, 3, 9, 5, 2, 9, 3, 11, 1, 14, 5, 4, 12, 5, 3, 5, 11, 3, 11, 6, 13, 7, 13, 7, 4, 9, 4, 13, 8, 3, 5, 11},
+	{13, 12, 12, 13, 8, 2, 4, 2, 10, 6, 3, 5, 7, 7, 6, 13, 8, 6, 15, 4, 12, 7, 15, 4, 3, 9, 8, 15, 0, 3, 12, 1, 9, 8, 13, 10, 15, 4, 14, 1, 6, 15, 0, 4, 8, 9, 3, 1, 3, 15, 5, 5, 1, 11, 11, 10, 11, 10, 8, 8, 5, 4, 13, 0},
+	{8, 4, 15, 9, 14, 9, 5, 8, 8, 10, 5, 15, 9, 8, 12, 5, 11, 10, 2, 12, 13, 1, 0, 2, 6, 13, 11, 9, 12, 0, 5, 0, 11, 5, 14, 12, 3, 4, 2, 10, 3, 12, 5, 15, 4, 8, 14, 1, 0, 13, 9, 5, 2, 4, 13, 8, 2, 5, 8, 9, 15, 3, 5, 5},
+	{0, 3, 3, 4, 6, 5, 5, 1, 3, 2, 14, 5, 10, 7, 15, 11, 7, 13, 15, 4, 0, 12, 9, 15, 12, 0, 3, 1, 14, 1, 12, 9, 13, 8, 9, 15, 12, 3, 5, 11, 3, 11, 4, 1, 9, 4, 13, 7, 4, 10, 6, 14, 13, 0, 9, 11, 15, 15, 3, 3, 13, 15, 10, 15},
+}

domain/consensus/utils/pow/pow.go

@@ -52,7 +52,10 @@ func CalculateProofOfWorkValue(header externalapi.MutableBlockHeader) *big.Int {
 	if err != nil {
 		panic(errors.Wrap(err, "this should never happen. Hash digest should never return an error"))
 	}
-	return toBig(writer.Finalize())
+	powHash := writer.Finalize()
+	matrix := generateMatrix(powHash)
+	heavyHash := matrix.HeavyHash(powHash)
+	return toBig(heavyHash)
 }
 
 // ToBig converts a externalapi.DomainHash into a big.Int treated as a little endian string.

domain/consensus/utils/pow/xoshiro.go

@@ -0,0 +1,37 @@
+package pow
+
+import (
+	"encoding/binary"
+	"github.com/kaspanet/kaspad/domain/consensus/model/externalapi"
+	"math/bits"
+)
+
+type xoShiRo256PlusPlus struct {
+	s0 uint64
+	s1 uint64
+	s2 uint64
+	s3 uint64
+}
+
+func newxoShiRo256PlusPlus(hash *externalapi.DomainHash) *xoShiRo256PlusPlus {
+	hashArray := hash.ByteArray()
+	return &xoShiRo256PlusPlus{
+		s0: binary.LittleEndian.Uint64(hashArray[:8]),
+		s1: binary.LittleEndian.Uint64(hashArray[8:16]),
+		s2: binary.LittleEndian.Uint64(hashArray[16:24]),
+		s3: binary.LittleEndian.Uint64(hashArray[24:32]),
+	}
+}
+
+func (x *xoShiRo256PlusPlus) Uint64() uint64 {
+	res := bits.RotateLeft64(x.s0+x.s3, 23) + x.s0
+	t := x.s1 << 17
+	x.s2 ^= x.s0
+	x.s3 ^= x.s1
+	x.s1 ^= x.s2
+	x.s0 ^= x.s3
+
+	x.s2 ^= t
+	x.s3 = bits.RotateLeft64(x.s3, 45)
+	return res
+}

domain/consensus/utils/pow/xoshiro_test.go

@@ -0,0 +1,17 @@
+package pow
+
+import "testing"
+
+// Test vectors are from here: https://github.com/rust-random/rngs/blob/17aa826cc38d3e8408c9489ac859fa9397acd479/rand_xoshiro/src/xoshiro256plusplus.rs#L121
+func TestXoShiRo256PlusPlus_Uint64(t *testing.T) {
+	state := xoShiRo256PlusPlus{1, 2, 3, 4}
+	expected := []uint64{41943041, 58720359, 3588806011781223, 3591011842654386,
+		9228616714210784205, 9973669472204895162, 14011001112246962877,
+		12406186145184390807, 15849039046786891736, 10450023813501588000}
+	for _, ex := range expected {
+		val := state.Uint64()
+		if val != ex {
+			t.Errorf("expected: %d, found: %d", ex, val)
+		}
+	}
+}