@@ -67,29 +67,68 @@ func hashPointToR(pubs []kyber.Point) ([]kyber.Scalar, error) {
6767 return coefs , nil
6868}
6969
70+ type Scheme struct {
71+ blsScheme sign.AggregatableScheme
72+ sigGroup kyber.Group
73+ keyGroup kyber.Group
74+ pairing func (signature , public , hashedPoint kyber.Point ) bool
75+ }
76+
77+ // NewSchemeOnG1 returns a sign.Scheme that uses G1 for its signature space and G2
78+ // for its public keys
79+ func NewSchemeOnG1 (suite pairing.Suite ) * Scheme {
80+ sigGroup := suite .G1 ()
81+ keyGroup := suite .G2 ()
82+ pairing := func (public , hashedMsg , sigPoint kyber.Point ) bool {
83+ return suite .ValidatePairing (hashedMsg , public , sigPoint , keyGroup .Point ().Base ())
84+ }
85+ return & Scheme {
86+ blsScheme : bls .NewSchemeOnG1 (suite ),
87+ sigGroup : sigGroup ,
88+ keyGroup : keyGroup ,
89+ pairing : pairing ,
90+ }
91+ }
92+
93+ // NewSchemeOnG2 returns a sign.Scheme that uses G2 for its signature space and
94+ // G1 for its public key
95+ func NewSchemeOnG2 (suite pairing.Suite ) * Scheme {
96+ sigGroup := suite .G2 ()
97+ keyGroup := suite .G1 ()
98+ pairing := func (public , hashedMsg , sigPoint kyber.Point ) bool {
99+ return suite .ValidatePairing (public , hashedMsg , keyGroup .Point ().Base (), sigPoint )
100+ }
101+ return & Scheme {
102+ blsScheme : bls .NewSchemeOnG2 (suite ),
103+ sigGroup : sigGroup ,
104+ keyGroup : keyGroup ,
105+ pairing : pairing ,
106+ }
107+ }
108+
70109// NewKeyPair creates a new BLS signing key pair. The private key x is a scalar
71- // and the public key X is a point on curve G2 .
72- func NewKeyPair ( suite pairing. Suite , random cipher.Stream ) (kyber.Scalar , kyber.Point ) {
73- return bls . NewSchemeOnG1 ( suite ) .NewKeyPair (random )
110+ // and the public key X is a point on the scheme's key group .
111+ func ( scheme * Scheme ) NewKeyPair ( random cipher.Stream ) (kyber.Scalar , kyber.Point ) {
112+ return scheme . blsScheme .NewKeyPair (random )
74113}
75114
76115// Sign creates a BLS signature S = x * H(m) on a message m using the private
77- // key x. The signature S is a point on curve G1 .
78- func Sign ( suite pairing. Suite , x kyber.Scalar , msg []byte ) ([]byte , error ) {
79- return bls . NewSchemeOnG1 ( suite ) .Sign (x , msg )
116+ // key x. The signature S is a point on the scheme's signature group .
117+ func ( scheme * Scheme ) Sign ( x kyber.Scalar , msg []byte ) ([]byte , error ) {
118+ return scheme . blsScheme .Sign (x , msg )
80119}
81120
82121// Verify checks the given BLS signature S on the message m using the public
83122// key X by verifying that the equality e(H(m), X) == e(H(m), x*B2) ==
84123// e(x*H(m), B2) == e(S, B2) holds where e is the pairing operation and B2 is
85- // the base point from curve G2 .
86- func Verify ( suite pairing. Suite , x kyber.Point , msg , sig []byte ) error {
87- return bls . NewSchemeOnG1 ( suite ) .Verify (x , msg , sig )
124+ // the base point from the scheme's key group .
125+ func ( scheme * Scheme ) Verify ( x kyber.Point , msg , sig []byte ) error {
126+ return scheme . blsScheme .Verify (x , msg , sig )
88127}
89128
90129// AggregateSignatures aggregates the signatures using a coefficient for each
91- // one of them where c = H(pk) and H: G2 -> R with R = {1, ..., 2^128}
92- func AggregateSignatures ( suite pairing. Suite , sigs [][]byte , mask * sign.Mask ) (kyber.Point , error ) {
130+ // one of them where c = H(pk) and H: keyGroup -> R with R = {1, ..., 2^128}
131+ func ( scheme * Scheme ) AggregateSignatures ( sigs [][]byte , mask * sign.Mask ) (kyber.Point , error ) {
93132 if len (sigs ) != mask .CountEnabled () {
94133 return nil , errors .New ("length of signatures and public keys must match" )
95134 }
@@ -99,7 +138,7 @@ func AggregateSignatures(suite pairing.Suite, sigs [][]byte, mask *sign.Mask) (k
99138 return nil , err
100139 }
101140
102- agg := suite . G1 () .Point ()
141+ agg := scheme . sigGroup .Point ()
103142 for i , buf := range sigs {
104143 peerIndex := mask .IndexOfNthEnabled (i )
105144 if peerIndex < 0 {
@@ -108,7 +147,7 @@ func AggregateSignatures(suite pairing.Suite, sigs [][]byte, mask *sign.Mask) (k
108147 return nil , errors .New ("couldn't find the index" )
109148 }
110149
111- sig := suite . G1 () .Point ()
150+ sig := scheme . sigGroup .Point ()
112151 err = sig .UnmarshalBinary (buf )
113152 if err != nil {
114153 return nil , err
@@ -125,14 +164,14 @@ func AggregateSignatures(suite pairing.Suite, sigs [][]byte, mask *sign.Mask) (k
125164
126165// AggregatePublicKeys aggregates a set of public keys (similarly to
127166// AggregateSignatures for signatures) using the hash function
128- // H: G2 -> R with R = {1, ..., 2^128}.
129- func AggregatePublicKeys ( suite pairing. Suite , mask * sign.Mask ) (kyber.Point , error ) {
167+ // H: keyGroup -> R with R = {1, ..., 2^128}.
168+ func ( scheme * Scheme ) AggregatePublicKeys ( mask * sign.Mask ) (kyber.Point , error ) {
130169 coefs , err := hashPointToR (mask .Publics ())
131170 if err != nil {
132171 return nil , err
133172 }
134173
135- agg := suite . G2 () .Point ()
174+ agg := scheme . keyGroup .Point ()
136175 for i := 0 ; i < mask .CountEnabled (); i ++ {
137176 peerIndex := mask .IndexOfNthEnabled (i )
138177 if peerIndex < 0 {
@@ -149,3 +188,43 @@ func AggregatePublicKeys(suite pairing.Suite, mask *sign.Mask) (kyber.Point, err
149188
150189 return agg , nil
151190}
191+
192+ // v1 API Deprecated ----------------------------------
193+
194+ // NewKeyPair creates a new BLS signing key pair. The private key x is a scalar
195+ // and the public key X is a point on curve G2.
196+ // Deprecated: use the new scheme methods instead.
197+ func NewKeyPair (suite pairing.Suite , random cipher.Stream ) (kyber.Scalar , kyber.Point ) {
198+ return NewSchemeOnG1 (suite ).NewKeyPair (random )
199+ }
200+
201+ // Sign creates a BLS signature S = x * H(m) on a message m using the private
202+ // key x. The signature S is a point on curve G1.
203+ // Deprecated: use the new scheme methods instead.
204+ func Sign (suite pairing.Suite , x kyber.Scalar , msg []byte ) ([]byte , error ) {
205+ return NewSchemeOnG1 (suite ).Sign (x , msg )
206+ }
207+
208+ // Verify checks the given BLS signature S on the message m using the public
209+ // key X by verifying that the equality e(H(m), X) == e(H(m), x*B2) ==
210+ // e(x*H(m), B2) == e(S, B2) holds where e is the pairing operation and B2 is
211+ // the base point from curve G2.
212+ // Deprecated: use the new scheme methods instead.
213+ func Verify (suite pairing.Suite , x kyber.Point , msg , sig []byte ) error {
214+ return NewSchemeOnG1 (suite ).Verify (x , msg , sig )
215+ }
216+
217+ // AggregateSignatures aggregates the signatures using a coefficient for each
218+ // one of them where c = H(pk) and H: G2 -> R with R = {1, ..., 2^128}
219+ // Deprecated: use the new scheme methods instead.
220+ func AggregateSignatures (suite pairing.Suite , sigs [][]byte , mask * sign.Mask ) (kyber.Point , error ) {
221+ return NewSchemeOnG1 (suite ).AggregateSignatures (sigs , mask )
222+ }
223+
224+ // AggregatePublicKeys aggregates a set of public keys (similarly to
225+ // AggregateSignatures for signatures) using the hash function
226+ // H: G2 -> R with R = {1, ..., 2^128}.
227+ // Deprecated: use the new scheme methods instead.
228+ func AggregatePublicKeys (suite pairing.Suite , mask * sign.Mask ) (kyber.Point , error ) {
229+ return NewSchemeOnG1 (suite ).AggregatePublicKeys (mask )
230+ }
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