From 16a8a18a6d3c81e737041beaadc73964c4285a3a Mon Sep 17 00:00:00 2001 From: arnaucube Date: Thu, 5 Mar 2020 17:35:25 +0100 Subject: [PATCH 1/2] Optimize MiMC7 migrating from *big.Int to goff Optimize MiMC7 migrating from *big.Int to goff generated finite field operations. There is still a lot of room for optimization for MiMC7 in the way that is done internally, but will be done in the future. Benchmarks: Tested on a Intel(R) Core(TM) i5-7200U CPU @ 2.50GHz, with 16GB of RAM. - Before: ``` BenchmarkMIMC7-4 1026 1160298 ns/op ``` - After this commit: ``` BenchmarkMIMC7-4 19263 61651 ns/op ``` --- mimc7/mimc7.go | 95 ++++++++++++++++++++++++-------------------- mimc7/mimc7_test.go | 10 ++--- poseidon/poseidon.go | 1 - 3 files changed, 55 insertions(+), 51 deletions(-) diff --git a/mimc7/mimc7.go b/mimc7/mimc7.go index f323b33..d01a6b5 100644 --- a/mimc7/mimc7.go +++ b/mimc7/mimc7.go @@ -6,7 +6,7 @@ import ( "github.com/ethereum/go-ethereum/crypto" _constants "github.com/iden3/go-iden3-crypto/constants" - "github.com/iden3/go-iden3-crypto/field" + "github.com/iden3/go-iden3-crypto/ff" "github.com/iden3/go-iden3-crypto/utils" ) @@ -15,73 +15,72 @@ const SEED = "mimc" var constants = generateConstantsData() type constantsData struct { - maxFieldVal *big.Int - seedHash *big.Int - iv *big.Int - fqR field.Fq - nRounds int - cts []*big.Int + seedHash *big.Int + iv *big.Int + nRounds int + cts []*ff.Element } func generateConstantsData() constantsData { var constants constantsData - fqR := field.NewFq(_constants.Q) - constants.fqR = fqR - - // maxFieldVal is the R value of the Finite Field - constants.maxFieldVal = constants.fqR.Q - constants.seedHash = new(big.Int).SetBytes(crypto.Keccak256([]byte(SEED))) c := new(big.Int).SetBytes(crypto.Keccak256([]byte(SEED + "_iv"))) - constants.iv = new(big.Int).Mod(c, constants.maxFieldVal) + constants.iv = new(big.Int).Mod(c, _constants.Q) constants.nRounds = 91 - cts := getConstants(constants.fqR, SEED, constants.nRounds) + cts := getConstants(SEED, constants.nRounds) constants.cts = cts return constants } -func getConstants(fqR field.Fq, seed string, nRounds int) []*big.Int { - cts := make([]*big.Int, nRounds) - cts[0] = big.NewInt(int64(0)) +func getConstants(seed string, nRounds int) []*ff.Element { + cts := make([]*ff.Element, nRounds) + cts[0] = ff.NewElement().SetZero() c := new(big.Int).SetBytes(crypto.Keccak256([]byte(SEED))) for i := 1; i < nRounds; i++ { c = new(big.Int).SetBytes(crypto.Keccak256(c.Bytes())) - n := fqR.Affine(c) - cts[i] = n + n := new(big.Int).Mod(c, _constants.Q) + cts[i] = ff.NewElement().SetBigInt(n) } return cts } // MIMC7HashGeneric performs the MIMC7 hash over a *big.Int, in a generic way, where it can be specified the Finite Field over R, and the number of rounds -func MIMC7HashGeneric(fqR field.Fq, xIn, k *big.Int, nRounds int) *big.Int { - cts := getConstants(fqR, SEED, nRounds) - var r *big.Int +func MIMC7HashGeneric(xInBI, kBI *big.Int, nRounds int) *big.Int { + xIn := ff.NewElement().SetBigInt(xInBI) + k := ff.NewElement().SetBigInt(kBI) + + cts := getConstants(SEED, nRounds) + var r *ff.Element for i := 0; i < nRounds; i++ { - var t *big.Int + var t *ff.Element if i == 0 { - t = fqR.Add(xIn, k) + t = ff.NewElement().Add(xIn, k) } else { - t = fqR.Add(fqR.Add(r, k), cts[i]) + t = ff.NewElement().Add(ff.NewElement().Add(r, k), cts[i]) } - t2 := fqR.Square(t) - t4 := fqR.Square(t2) - r = fqR.Mul(fqR.Mul(t4, t2), t) + t2 := ff.NewElement().Square(t) + t4 := ff.NewElement().Square(t2) + r = ff.NewElement().Mul(ff.NewElement().Mul(t4, t2), t) } - return fqR.Affine(fqR.Add(r, k)) + rE := ff.NewElement().Add(r, k) + + res := big.NewInt(0) + rE.ToBigIntRegular(res) + return res } // HashGeneric performs the MIMC7 hash over a *big.Int array, in a generic way, where it can be specified the Finite Field over R, and the number of rounds -func HashGeneric(iv *big.Int, arr []*big.Int, fqR field.Fq, nRounds int) (*big.Int, error) { +func HashGeneric(iv *big.Int, arr []*big.Int, nRounds int) (*big.Int, error) { if !utils.CheckBigIntArrayInField(arr) { return nil, errors.New("inputs values not inside Finite Field") } r := iv var err error for i := 0; i < len(arr); i++ { - r = MIMC7HashGeneric(fqR, r, arr[i], nRounds) + r = MIMC7HashGeneric(r, arr[i], nRounds) if err != nil { return r, err } @@ -90,20 +89,27 @@ func HashGeneric(iv *big.Int, arr []*big.Int, fqR field.Fq, nRounds int) (*big.I } // MIMC7Hash performs the MIMC7 hash over a *big.Int, using the Finite Field over R and the number of rounds setted in the `constants` variable -func MIMC7Hash(xIn, k *big.Int) *big.Int { - var r *big.Int +func MIMC7Hash(xInBI, kBI *big.Int) *big.Int { + xIn := ff.NewElement().SetBigInt(xInBI) + k := ff.NewElement().SetBigInt(kBI) + + var r *ff.Element for i := 0; i < constants.nRounds; i++ { - var t *big.Int + var t *ff.Element if i == 0 { - t = constants.fqR.Add(xIn, k) + t = ff.NewElement().Add(xIn, k) } else { - t = constants.fqR.Add(constants.fqR.Add(r, k), constants.cts[i]) + t = ff.NewElement().Add(ff.NewElement().Add(r, k), constants.cts[i]) } - t2 := constants.fqR.Square(t) - t4 := constants.fqR.Square(t2) - r = constants.fqR.Mul(constants.fqR.Mul(t4, t2), t) + t2 := ff.NewElement().Square(t) + t4 := ff.NewElement().Square(t2) + r = ff.NewElement().Mul(ff.NewElement().Mul(t4, t2), t) } - return constants.fqR.Affine(constants.fqR.Add(r, k)) + rE := ff.NewElement().Add(r, k) + + res := big.NewInt(0) + rE.ToBigIntRegular(res) + return res } // Hash performs the MIMC7 hash over a *big.Int array @@ -113,17 +119,18 @@ func Hash(arr []*big.Int, key *big.Int) (*big.Int, error) { } var r *big.Int if key == nil { - r = constants.fqR.Zero() + r = big.NewInt(0) } else { r = key } for i := 0; i < len(arr); i++ { - r = constants.fqR.Add( - constants.fqR.Add( + r = new(big.Int).Add( + new(big.Int).Add( r, arr[i], ), MIMC7Hash(arr[i], r)) + r = new(big.Int).Mod(r, _constants.Q) } return r, nil } diff --git a/mimc7/mimc7_test.go b/mimc7/mimc7_test.go index 990cefa..004c2cf 100644 --- a/mimc7/mimc7_test.go +++ b/mimc7/mimc7_test.go @@ -6,7 +6,6 @@ import ( "testing" "github.com/ethereum/go-ethereum/crypto" - "github.com/iden3/go-iden3-crypto/field" "github.com/stretchr/testify/assert" ) @@ -22,16 +21,15 @@ func TestMIMC7Generic(t *testing.T) { b2 := big.NewInt(int64(2)) b3 := big.NewInt(int64(3)) - r, ok := new(big.Int).SetString("21888242871839275222246405745257275088548364400416034343698204186575808495617", 10) - assert.True(t, ok) - fqR := field.NewFq(r) + // r, ok := new(big.Int).SetString("21888242871839275222246405745257275088548364400416034343698204186575808495617", 10) + // assert.True(t, ok) bigArray := []*big.Int{b1, b2, b3} // Generic Hash - mhg := MIMC7HashGeneric(fqR, b1, b2, 91) + mhg := MIMC7HashGeneric(b1, b2, 91) assert.Equal(t, "10594780656576967754230020536574539122676596303354946869887184401991294982664", mhg.String()) - hg, err := HashGeneric(fqR.Zero(), bigArray, fqR, 91) + hg, err := HashGeneric(big.NewInt(0), bigArray, 91) assert.Nil(t, err) assert.Equal(t, "6464402164086696096195815557694604139393321133243036833927490113253119343397", (*big.Int)(hg).String()) } diff --git a/poseidon/poseidon.go b/poseidon/poseidon.go index a5dc7b0..26bc704 100644 --- a/poseidon/poseidon.go +++ b/poseidon/poseidon.go @@ -92,7 +92,6 @@ func ark(state [T]*ff.Element, c *ff.Element) { // cubic performs x^5 mod p // https://eprint.iacr.org/2019/458.pdf page 8 -// var five = big.NewInt(5) func cubic(a *ff.Element) { a.Exp(*a, 5) From 4750e9c83cbc89c26a69d70860354855893fd5c5 Mon Sep 17 00:00:00 2001 From: arnaucube Date: Thu, 5 Mar 2020 17:39:51 +0100 Subject: [PATCH 2/2] Remove field package which is no longer used --- field/field.go | 152 ------------------------------------------- field/field_test.go | 39 ----------- mimc7/mimc7.go | 2 +- mimc7/mimc7_test.go | 3 - poseidon/poseidon.go | 4 +- 5 files changed, 3 insertions(+), 197 deletions(-) delete mode 100644 field/field.go delete mode 100644 field/field_test.go diff --git a/field/field.go b/field/field.go deleted file mode 100644 index 4f4f44a..0000000 --- a/field/field.go +++ /dev/null @@ -1,152 +0,0 @@ -// code originally taken from https://github.com/arnaucube/go-snark (https://github.com/arnaucube/go-snark/blob/master/fields/fq.go), pasted here to ensure compatibility among future changes - -package field - -import ( - "bytes" - "crypto/rand" - "math/big" -) - -// Fq is the Z field over modulus Q -type Fq struct { - Q *big.Int // Q -} - -// NewFq generates a new Fq -func NewFq(q *big.Int) Fq { - return Fq{ - q, - } -} - -// Zero returns a Zero value on the Fq -func (fq Fq) Zero() *big.Int { - return big.NewInt(int64(0)) -} - -// One returns a One value on the Fq -func (fq Fq) One() *big.Int { - return big.NewInt(int64(1)) -} - -// Add performs an addition on the Fq -func (fq Fq) Add(a, b *big.Int) *big.Int { - r := new(big.Int).Add(a, b) - return new(big.Int).Mod(r, fq.Q) -} - -// Double performs a doubling on the Fq -func (fq Fq) Double(a *big.Int) *big.Int { - r := new(big.Int).Add(a, a) - return new(big.Int).Mod(r, fq.Q) -} - -// Sub performs a subtraction on the Fq -func (fq Fq) Sub(a, b *big.Int) *big.Int { - r := new(big.Int).Sub(a, b) - return new(big.Int).Mod(r, fq.Q) -} - -// Neg performs a negation on the Fq -func (fq Fq) Neg(a *big.Int) *big.Int { - m := new(big.Int).Neg(a) - return new(big.Int).Mod(m, fq.Q) -} - -// Mul performs a multiplication on the Fq -func (fq Fq) Mul(a, b *big.Int) *big.Int { - m := new(big.Int).Mul(a, b) - return new(big.Int).Mod(m, fq.Q) -} - -func (fq Fq) MulScalar(base, e *big.Int) *big.Int { - return fq.Mul(base, e) -} - -// Inverse returns the inverse on the Fq -func (fq Fq) Inverse(a *big.Int) *big.Int { - return new(big.Int).ModInverse(a, fq.Q) -} - -// Div performs the division over the finite field -func (fq Fq) Div(a, b *big.Int) *big.Int { - d := fq.Mul(a, fq.Inverse(b)) - return new(big.Int).Mod(d, fq.Q) -} - -// Square performs a square operation on the Fq -func (fq Fq) Square(a *big.Int) *big.Int { - m := new(big.Int).Mul(a, a) - return new(big.Int).Mod(m, fq.Q) -} - -// Exp performs the exponential over Fq -func (fq Fq) Exp(base *big.Int, e *big.Int) *big.Int { - res := fq.One() - rem := fq.Copy(e) - exp := base - - for !bytes.Equal(rem.Bytes(), big.NewInt(int64(0)).Bytes()) { - if BigIsOdd(rem) { - res = fq.Mul(res, exp) - } - exp = fq.Square(exp) - rem = new(big.Int).Rsh(rem, 1) - } - return res -} - -func (fq Fq) Rand() (*big.Int, error) { - - maxbits := fq.Q.BitLen() - b := make([]byte, (maxbits/8)-1) - _, err := rand.Read(b) - if err != nil { - return nil, err - } - r := new(big.Int).SetBytes(b) - rq := new(big.Int).Mod(r, fq.Q) - - // r over q, nil - return rq, nil -} - -func (fq Fq) IsZero(a *big.Int) bool { - return bytes.Equal(a.Bytes(), fq.Zero().Bytes()) -} - -func (fq Fq) Copy(a *big.Int) *big.Int { - return new(big.Int).SetBytes(a.Bytes()) -} - -func (fq Fq) Affine(a *big.Int) *big.Int { - nq := fq.Neg(fq.Q) - - aux := a - if aux.Cmp(big.NewInt(int64(0))) == -1 { // negative value - if aux.Cmp(nq) != 1 { // aux less or equal nq - aux = new(big.Int).Mod(aux, fq.Q) - } - if aux.Cmp(big.NewInt(int64(0))) == -1 { // negative value - aux = new(big.Int).Add(aux, fq.Q) - } - } else { - if aux.Cmp(fq.Q) != -1 { // aux greater or equal nq - aux = new(big.Int).Mod(aux, fq.Q) - } - } - return aux -} - -func (fq Fq) Equal(a, b *big.Int) bool { - aAff := fq.Affine(a) - bAff := fq.Affine(b) - return bytes.Equal(aAff.Bytes(), bAff.Bytes()) -} - -func BigIsOdd(n *big.Int) bool { - one := big.NewInt(int64(1)) - and := new(big.Int).And(n, one) - return bytes.Equal(and.Bytes(), big.NewInt(int64(1)).Bytes()) -} diff --git a/field/field_test.go b/field/field_test.go deleted file mode 100644 index 0717a16..0000000 --- a/field/field_test.go +++ /dev/null @@ -1,39 +0,0 @@ -// code originally taken from https://github.com/arnaucube/go-snark (https://github.com/arnaucube/go-snark/blob/master/fields/fq.go), pasted here to ensure compatibility among future changes - -package field - -import ( - "math/big" - "testing" - - "github.com/stretchr/testify/assert" -) - -func iToBig(a int) *big.Int { - return big.NewInt(int64(a)) -} - -func TestFq1(t *testing.T) { - fq1 := NewFq(iToBig(7)) - - res := fq1.Add(iToBig(4), iToBig(4)) - assert.Equal(t, iToBig(1), fq1.Affine(res)) - - res = fq1.Double(iToBig(5)) - assert.Equal(t, iToBig(3), fq1.Affine(res)) - - res = fq1.Sub(iToBig(5), iToBig(7)) - assert.Equal(t, iToBig(5), fq1.Affine(res)) - - res = fq1.Neg(iToBig(5)) - assert.Equal(t, iToBig(2), fq1.Affine(res)) - - res = fq1.Mul(iToBig(5), iToBig(11)) - assert.Equal(t, iToBig(6), fq1.Affine(res)) - - res = fq1.Inverse(iToBig(4)) - assert.Equal(t, iToBig(2), res) - - res = fq1.Square(iToBig(5)) - assert.Equal(t, iToBig(4), res) -} diff --git a/mimc7/mimc7.go b/mimc7/mimc7.go index d01a6b5..ed3114f 100644 --- a/mimc7/mimc7.go +++ b/mimc7/mimc7.go @@ -36,7 +36,7 @@ func generateConstantsData() constantsData { func getConstants(seed string, nRounds int) []*ff.Element { cts := make([]*ff.Element, nRounds) - cts[0] = ff.NewElement().SetZero() + cts[0] = ff.NewElement() c := new(big.Int).SetBytes(crypto.Keccak256([]byte(SEED))) for i := 1; i < nRounds; i++ { c = new(big.Int).SetBytes(crypto.Keccak256(c.Bytes())) diff --git a/mimc7/mimc7_test.go b/mimc7/mimc7_test.go index 004c2cf..55bfdf9 100644 --- a/mimc7/mimc7_test.go +++ b/mimc7/mimc7_test.go @@ -21,9 +21,6 @@ func TestMIMC7Generic(t *testing.T) { b2 := big.NewInt(int64(2)) b3 := big.NewInt(int64(3)) - // r, ok := new(big.Int).SetString("21888242871839275222246405745257275088548364400416034343698204186575808495617", 10) - // assert.True(t, ok) - bigArray := []*big.Int{b1, b2, b3} // Generic Hash diff --git a/poseidon/poseidon.go b/poseidon/poseidon.go index 26bc704..4a04de0 100644 --- a/poseidon/poseidon.go +++ b/poseidon/poseidon.go @@ -20,7 +20,7 @@ var constC []*ff.Element var constM [T][T]*ff.Element func Zero() *ff.Element { - return ff.NewElement().SetZero() + return ff.NewElement() } func modQ(v *big.Int) { @@ -71,7 +71,7 @@ func getMDS() [T][T]*ff.Element { func checkAllDifferent(v []*ff.Element) bool { for i := 0; i < len(v); i++ { - if v[i].Equal(ff.NewElement().SetZero()) { + if v[i].Equal(ff.NewElement()) { return false } for j := i + 1; j < len(v); j++ {