Fixed

cmd/handin6/main.go

@@ -78,7 +78,8 @@ type Protocol struct {
 
 func NewProtocol() (p *Protocol, err error) {
 	conn := make(chan big.Int)
-	sKey, HEp, err := homomorphic.NewProtocol(3,27)
+	params := homomorphic.NewParams(200,100000, 1000000,200)
+	sKey, HEp, err := homomorphic.NewProtocol(params)
 	if err != nil {
 		return
 	}

internal/crypto/homomorphic/dhe.go

 package homomorphic
 
 import (
-	"math/big"
+	"crycomp/internal/crypto/util"
 	"crypto/rand"
+	"math/big"
 	mRand "math/rand"
-	
 )
 
+type Params struct {
+	len_sKey int
+	len_q int
+	len_r int
+	m int
+}
+func NewParams(len_sKey, len_q, len_r, m int) *Params {
+	return &Params{
+		len_sKey : len_sKey,
+		len_q : len_q,
+		len_r : len_r,
+		m : m,
+	}
+}
+
 type Protocol struct {
-	d, n int
 	pubKey []*big.Int
+	params *Params
 }
 
-func NewProtocol(d, n int) (sKey *big.Int, pr Protocol, err error) {
-	s_int, b_int := big.NewInt(27), big.NewInt(27)
-	sBytes := make([]byte, 250)
-	_, err = rand.Read(sBytes)
+func NewProtocol(params *Params) (sKey *big.Int, pr Protocol, err error) {
+	//set private key to a random odd 2000-bit integer
+	res, err := util.RandInt(rand.Reader, big.NewInt(int64(params.len_sKey)))
 	if err != nil {return}
-	sBytes[len(sBytes)]
-	sKey = sKey.SetBit(sKey, 0, 1)
+	res.SetBit(res, 0, 1)
+	sKey = res
 
-	q := make([]*big.Int, n)
-	r := make([]*big.Int, n)
-	y := make([]*big.Int, n)
+	q := make([]*big.Int, params.m)
+	r := make([]*big.Int, params.m)
+	y := make([]*big.Int, params.m)
 
 	for i := range q {
-		q[i], err = rand.Int(rand.Reader, b_int)
+		q[i], err = rand.Int(rand.Reader, big.NewInt(int64(params.len_q)))
 		if err != nil {return}
-		r[i], err = rand.Int(rand.Reader, s_int)
+		r[i], err = rand.Int(rand.Reader, big.NewInt(int64(params.len_r)))
 		if err != nil {return}
 		right := big.NewInt(2)
 		right.Mul(right,r[i])
@@ -35,21 +49,20 @@ func NewProtocol(d, n int) (sKey *big.Int, pr Protocol, err error) {
 		y[i] = right.Add(left, right)
 	}
 	pr = Protocol{
-		n : n,
-		d : d,
 		pubKey : y,
+		params : params,
 	}
 	return sKey, pr, err
 }
 
 func (p *Protocol) Encode(m int) (c *big.Int) {
 	SLen := 4 //TODO: Define actual value
-	S := make([]int, p.n)
-	for i := 0; i < p.n; i++ {
+	S := make([]int, p.params.m)
+	for i := 0; i < p.params.m; i++ {
 		S[i] = i
 	}
-	mRand.Shuffle(p.n, func(i,j int) {S[i],S[j] = S[j], S[i]})
-	S = S[:SLen]
+	mRand.Shuffle(p.params.m, func(i,j int) {S[i],S[j] = S[j], S[i]})
+	S = S[:SLen-1]
 	c = big.NewInt(int64(m))
 	for i := range S {
 		c = c.Add(c, p.pubKey[S[i]])

internal/crypto/util/util.go

@@ -72,4 +72,4 @@ func (s *cryptoSource) Int63() int64 {
 
 func (s *cryptoSource) Seed(seed int64) {
 	panic("seed")
-}
+}
\ No newline at end of file