Merge pull request #504 from tuneinsight/integrity-across-versions

Serialization inconsistency detection

core/rlwe/encryptor.go

@@ -99,6 +99,29 @@ func newEncryptor(params Parameters) *Encryptor {
 	}
 }
 
+// NewTestEncryptorWithPRNG creates a new [Encryptor] that uses the provided prng for randomness.
+// CAUTION: THIS FUNCTION SHOULD BE USED FOR TESTING PURPOSES ONLY.
+func NewTestEncryptorWithPRNG(params ParameterProvider, key EncryptionKey, prng sampling.PRNG) *Encryptor {
+	p := *params.GetRLWEParameters()
+
+	enc := NewEncryptor(params, key)
+	xeSampler, err := ring.NewSampler(prng, p.RingQ(), p.Xe(), false)
+	if err != nil {
+		panic(fmt.Errorf("NewEncryptorWithPRNG: cannot create xeSampler %w", err))
+	}
+	xsSampler, err := ring.NewSampler(prng, p.RingQ(), p.Xs(), false)
+	if err != nil {
+		panic(fmt.Errorf("NewEncryptorWithPRNG: cannot create xsSampler %w", err))
+	}
+	uniformSampler := ringqp.NewUniformSampler(prng, *p.RingQP())
+	enc.prng = prng
+	enc.xeSampler = xeSampler
+	enc.xsSampler = xsSampler
+	enc.uniformSampler = uniformSampler
+
+	return enc
+}
+
 type encryptorBuffers struct {
 	buffQP [3]ringqp.Poly
 }

core/rlwe/rlwe_test.go

@@ -1,13 +1,16 @@
 package rlwe
 
 import (
+	"encoding/base64"
 	"encoding/json"
 	"flag"
 	"fmt"
 	"math"
 	"runtime"
 	"testing"
 
+	"golang.org/x/crypto/blake2b"
+
 	"github.com/stretchr/testify/require"
 
 	"github.com/tuneinsight/lattigo/v6/ring"
@@ -31,6 +34,86 @@ func testString(params Parameters, levelQ, levelP, bpw2 int, opname string) stri
 		params.RingType())
 }
 
+// TestRLWEConstSerialization test detects (fails) if the serialization of
+// [PublicKey], [SecretKey], [Ciphertext], [GaloisKey], [MemEvaluationKeySet] has changed.
+// If such a modification is intended, this test must be updated and users notified s.t.
+// old serialized objects can be converted to the new format.
+func TestRLWEConstSerialization(t *testing.T) {
+	// Note: changing nbIteration will change the expected value
+	const nbIteration = 10
+	const expected = "XRdlwx5vEX9qdGY3CeeAxzGHa0gbXghzpLhV0eIgVk8="
+	var err error
+	defaultParamsLiteral := testInsecure
+	seedKeyGen := []byte{'l', 'a', 't'}
+	seedEnc := []byte{'t', 'i', 'g', 'o'}
+	hash, err := blake2b.New(32, nil)
+	require.Nil(t, err)
+
+	for _, paramsLit := range defaultParamsLiteral[:] {
+
+		for _, NTTFlag := range []bool{true, false}[:] {
+
+			for _, RingType := range []ring.Type{ring.Standard, ring.ConjugateInvariant}[:] {
+
+				paramsLit.NTTFlag = NTTFlag
+				paramsLit.RingType = RingType
+
+				var params Parameters
+				if params, err = NewParametersFromLiteral(paramsLit.ParametersLiteral); err != nil {
+					t.Fatal(err)
+				}
+
+				detTC, err := NewDeterministicTestContext(params, seedKeyGen, seedEnc)
+				require.Nil(t, err)
+				for i := 0; i < nbIteration; i++ {
+					// Add marshalled (sk, pk) to the hash input
+					sk, pk := detTC.kgen.GenKeyPairNew()
+					skBytes, err := sk.MarshalBinary()
+					hash.Write(skBytes)
+					require.Nil(t, err)
+
+					pkBytes, err := pk.MarshalBinary()
+					require.Nil(t, err)
+					hash.Write(pkBytes)
+
+					// Add marshalled GaloisKey to the hash input
+					galEl := params.GaloisElement(-1)
+					galEl2 := params.GaloisElement(3)
+					galKey := detTC.kgen.GenGaloisKeysNew([]uint64{galEl, galEl2}, sk)
+					galKeyBytes, err := galKey[0].MarshalBinary()
+					require.Nil(t, err)
+					hash.Write(galKeyBytes)
+
+					// Add marshalled MemEvaluationKeySet to the hash input
+					relinKey := detTC.kgen.GenRelinearizationKeyNew(sk)
+					evk := NewMemEvaluationKeySet(relinKey, galKey...)
+					evkBytes, err := evk.MarshalBinary()
+					require.Nil(t, err)
+					hash.Write(evkBytes)
+
+					// Add marshalled MemEvaluationKeySet to the hash input
+					ct := NewCiphertext(params, 1, params.MaxLevel())
+					pt := genPlaintext(params, params.MaxLevel(), (1<<int(params.LogQ()))-1)
+					detTC.enc.Encrypt(pt, ct)
+					ctBytes, err := ct.MarshalBinary()
+					require.Nil(t, err)
+					hash.Write(ctBytes)
+					ctJSON, err := ct.MarshalJSON()
+					require.Nil(t, err)
+					hash.Write(ctJSON)
+				}
+			}
+		}
+	}
+
+	digest := base64.StdEncoding.EncodeToString(hash.Sum(nil))
+
+	// In case the value expected must be updated, uncomment to print the new expected value:
+	// fmt.Println(digest)
+
+	require.Equal(t, expected, digest)
+}
+
 func TestRLWE(t *testing.T) {
 
 	var err error
@@ -219,6 +302,40 @@ func testUserDefinedParameters(t *testing.T) {
 
 }
 
+func NewDeterministicTestContext(params Parameters, seedKeyGen, seedEnc []byte) (tc *TestContext, err error) {
+	prngKGen, err := sampling.NewKeyedPRNG(seedKeyGen)
+	if err != nil {
+		panic(fmt.Errorf("NewDeterministicTestContext: failed to make prngKGen %w", err))
+	}
+	prngEnc, err := sampling.NewKeyedPRNG(seedEnc)
+	if err != nil {
+		panic(fmt.Errorf("NewDeterministicTestContext: failed to make prngEnc %w", err))
+	}
+	kgen := NewKeyGenerator(params)
+	kgenEncryptor := NewTestEncryptorWithPRNG(params, nil, prngKGen)
+	kgen.Encryptor = kgenEncryptor
+
+	sk := kgen.GenSecretKeyNew()
+
+	pk := kgen.GenPublicKeyNew(sk)
+
+	eval := NewEvaluator(params, nil)
+
+	enc := NewTestEncryptorWithPRNG(params, sk, prngEnc)
+
+	dec := NewDecryptor(params, sk)
+
+	return &TestContext{
+		params: params,
+		kgen:   kgen,
+		sk:     sk,
+		pk:     pk,
+		enc:    enc,
+		dec:    dec,
+		eval:   eval,
+	}, nil
+}
+
 func NewTestContext(params Parameters) (tc *TestContext, err error) {
 	kgen := NewKeyGenerator(params)
 	sk := kgen.GenSecretKeyNew()

schemes/bgv/bgv_test.go

@@ -1,6 +1,7 @@
 package bgv
 
 import (
+	"encoding/base64"
 	"encoding/json"
 	"flag"
 	"fmt"
@@ -9,6 +10,7 @@ import (
 	"testing"
 
 	"github.com/stretchr/testify/require"
+	"golang.org/x/crypto/blake2b"
 
 	"github.com/tuneinsight/lattigo/v6/core/rlwe"
 	"github.com/tuneinsight/lattigo/v6/ring"
@@ -871,6 +873,49 @@ func testEvaluatorBfv(tc *TestContext, t *testing.T) {
 	})
 }
 
+// TestBGVParamsConstSerialization test detects (fails) if the serialization of [Parameters] has changed.
+// If such a modification is intended, this test must be updated and users notified s.t.
+// old serialized parameters can be converted to the new format.
+func TestBGVParamsConstSerialization(t *testing.T) {
+	const expected = "7aw0pU3xCs2Hu8zHKqkPRUpltHC0+P+UxzMSqKJwSFs="
+	var err error
+	distribs := []ring.DistributionParameters{rlwe.DefaultXe, rlwe.DefaultXs, ring.Ternary{H: 192}}
+	hash, err := blake2b.New(32, nil)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	// Test with different CKKS params, including different plaintext moduli and distributions
+	for _, paramsLit := range []ParametersLiteral{ExampleParameters128BitLogN14LogQP438, testInsecure}[:] {
+		for _, ptMod := range testPlaintextModulus[:] {
+			for _, distXe := range distribs {
+				for _, distXs := range distribs {
+
+					paramsLit.Xe = distXe
+					paramsLit.Xs = distXs
+					paramsLit.PlaintextModulus = ptMod
+					var params Parameters
+					if params, err = NewParametersFromLiteral(paramsLit); err != nil {
+						t.Fatal(err)
+					}
+					paramsBytes, err := params.MarshalBinary()
+					require.Nil(t, err)
+					hash.Write(paramsBytes)
+					paramsBytes, err = params.MarshalJSON()
+					require.Nil(t, err)
+					hash.Write(paramsBytes)
+				}
+			}
+		}
+	}
+	digest := base64.StdEncoding.EncodeToString(hash.Sum(nil))
+
+	// In case the value expected must be updated, uncomment to print the new expected value:
+	// fmt.Println(digest)
+
+	require.Equal(t, expected, digest)
+}
+
 var (
 	// testInsecure are insecure parameters used for the sole purpose of fast testing.
 	testInsecure = ParametersLiteral{

schemes/ckks/ckks_test.go

@@ -1,6 +1,7 @@
 package ckks
 
 import (
+	"encoding/base64"
 	"encoding/json"
 	"flag"
 	"fmt"
@@ -10,6 +11,7 @@ import (
 	"testing"
 
 	"github.com/stretchr/testify/require"
+	"golang.org/x/crypto/blake2b"
 
 	"github.com/tuneinsight/lattigo/v6/core/rlwe"
 	"github.com/tuneinsight/lattigo/v6/ring"
@@ -798,6 +800,49 @@ func testBridge(tc *TestContext, t *testing.T) {
 	})
 }
 
+// TestCKKSParamsConstSerialization test detects (fails) if the serialization of [Parameters] has changed.
+// If such a modification is intended, this test must be updated and users notified s.t.
+// old serialized parameters can be converted to the new format.
+func TestCKKSParamsConstSerialization(t *testing.T) {
+	const expected = "Bo962QjkASlly6oMAojaEYOIGTh5v0nhzWvu93XgVRk="
+	var err error
+	distribs := []ring.DistributionParameters{rlwe.DefaultXe, rlwe.DefaultXs, ring.Ternary{H: 192}}
+	hash, err := blake2b.New(32, nil)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	// Test with different CKKS params, including different ringtypes and distributions
+	for _, paramsLit := range testParametersLiteral[:] {
+		for _, ringType := range []ring.Type{ring.Standard, ring.ConjugateInvariant}[:] {
+			for _, distXe := range distribs {
+				for _, distXs := range distribs {
+
+					paramsLit.RingType = ringType
+					paramsLit.Xe = distXe
+					paramsLit.Xs = distXs
+					var params Parameters
+					if params, err = NewParametersFromLiteral(paramsLit); err != nil {
+						t.Fatal(err)
+					}
+					paramsBytes, err := params.MarshalBinary()
+					require.Nil(t, err)
+					hash.Write(paramsBytes)
+					paramsBytes, err = params.MarshalJSON()
+					require.Nil(t, err)
+					hash.Write(paramsBytes)
+				}
+			}
+		}
+	}
+	digest := base64.StdEncoding.EncodeToString(hash.Sum(nil))
+
+	// In case the value expected must be updated, uncomment to print the new expected value:
+	// fmt.Println(digest)
+
+	require.Equal(t, expected, digest)
+}
+
 func name(opname string, tc *TestContext) string {
 
 	var precMode string