Fixed potential bugs related to ciphertext/plaintext allocation

bfv/plaintext.go

@@ -45,12 +45,8 @@ func NewPlaintextLvl(params Parameters, level int) *Plaintext {
 // where the message is set to the passed poly. No checks are performed on poly and
 // the returned Plaintext will share its backing array of coefficient.
 func NewPlaintextAtLevelFromPoly(level int, poly *ring.Poly) *Plaintext {
-	if len(poly.Coeffs) < level+1 {
-		panic("cannot NewPlaintextAtLevelFromPoly: provided ring.Poly level is too small")
-	}
-	v0 := new(ring.Poly)
-	v0.Coeffs = poly.Coeffs[:level+1]
-	return &Plaintext{Plaintext: &rlwe.Plaintext{Value: v0}}
+	pt := rlwe.NewPlaintextAtLevelFromPoly(level, poly)
+	return &Plaintext{Plaintext: pt}
 }
 
 // NewPlaintextRingT creates and allocates a new plaintext in RingT (single modulus T).

ckks/ciphertext.go

@@ -39,10 +39,9 @@ func NewCiphertextRandom(prng utils.PRNG, params Parameters, degree, level int,
 // where the message is set to the passed poly. No checks are performed on poly and
 // the returned Ciphertext will share its backing array of coefficient.
 func NewCiphertextAtLevelFromPoly(level int, poly [2]*ring.Poly) *Ciphertext {
-	v0, v1 := new(ring.Poly), new(ring.Poly)
-	v0.IsNTT, v1.IsNTT = true, true
-	v0.Coeffs, v1.Coeffs = poly[0].Coeffs[:level+1], poly[1].Coeffs[:level+1]
-	return &Ciphertext{Ciphertext: &rlwe.Ciphertext{Value: []*ring.Poly{v0, v1}}, Scale: 0}
+	ct := rlwe.NewCiphertextAtLevelFromPoly(level, poly)
+	ct.Value[0].IsNTT, ct.Value[1].IsNTT = true, true
+	return &Ciphertext{Ciphertext: ct, Scale: 0}
 }
 
 // ScalingFactor returns the scaling factor of the ciphertext

ckks/plaintext.go

@@ -32,8 +32,7 @@ func (p *Plaintext) SetScalingFactor(scale float64) {
 // where the message is set to the passed poly. No checks are performed on poly and
 // the returned Plaintext will share its backing array of coefficient.
 func NewPlaintextAtLevelFromPoly(level int, poly *ring.Poly) *Plaintext {
-	v0 := new(ring.Poly)
-	v0.IsNTT = true
-	v0.Coeffs = poly.Coeffs[:level+1]
-	return &Plaintext{Plaintext: &rlwe.Plaintext{Value: v0}, Scale: 0}
+	pt := rlwe.NewPlaintextAtLevelFromPoly(level, poly)
+	pt.Value.IsNTT = true
+	return &Plaintext{Plaintext: pt, Scale: 0}
 }

rlwe/elements.go

@@ -61,6 +61,19 @@ func NewPlaintext(params Parameters, level int) *Plaintext {
 	return &Plaintext{Value: ring.NewPoly(params.N(), level)}
 }
 
+// NewPlaintextAtLevelFromPoly construct a new Plaintext at a specific level
+// where the message is set to the passed poly. No checks are performed on poly and
+// the returned Plaintext will share its backing array of coefficient.
+func NewPlaintextAtLevelFromPoly(level int, poly *ring.Poly) *Plaintext {
+	if len(poly.Coeffs) < level+1 {
+		panic("cannot NewPlaintextAtLevelFromPoly: provided ring.Poly level is too small")
+	}
+	v0 := new(ring.Poly)
+	v0.Coeffs = poly.Coeffs[:level+1]
+	v0.Buff = poly.Buff[:poly.N()*(level+1)]
+	return &Plaintext{Value: v0}
+}
+
 // Degree returns the degree of the target element.
 func (pt Plaintext) Degree() int {
 	return 0
@@ -105,13 +118,13 @@ func NewCiphertextNTT(params Parameters, degree, level int) *Ciphertext {
 	return el
 }
 
-// NewCiphertextNTTAtLevelFromPoly construct a new Ciphetext at a specific level
+// NewCiphertextAtLevelFromPoly construct a new Ciphetext at a specific level
 // where the message is set to the passed poly. No checks are performed on poly and
 // the returned Ciphertext will share its backing array of coefficient.
-func NewCiphertextNTTAtLevelFromPoly(level int, poly [2]*ring.Poly) *Ciphertext {
+func NewCiphertextAtLevelFromPoly(level int, poly [2]*ring.Poly) *Ciphertext {
 	v0, v1 := new(ring.Poly), new(ring.Poly)
-	v0.IsNTT, v1.IsNTT = true, true
 	v0.Coeffs, v1.Coeffs = poly[0].Coeffs[:level+1], poly[1].Coeffs[:level+1]
+	v0.Buff, v1.Buff = poly[0].Buff[:poly[0].N()*(level+1)], poly[1].Buff[:poly[1].N()*(level+1)]
 	return &Ciphertext{Value: []*ring.Poly{v0, v1}}
 }
 

rlwe/evaluator_automorphism.go

@@ -177,7 +177,9 @@ func (eval *Evaluator) Trace(ctIn *Ciphertext, logN int, ctOut *Ciphertext) {
 			ring.MulScalarMontgomeryVec(ctIn.Value[1].Coeffs[i], ctOut.Value[1].Coeffs[i], invN, Q, mredparams)
 		}
 
-		buff := NewCiphertextNTTAtLevelFromPoly(levelQ, [2]*ring.Poly{eval.BuffQP[3].Q, eval.BuffQP[4].Q})
+		buff := NewCiphertextAtLevelFromPoly(levelQ, [2]*ring.Poly{eval.BuffQP[3].Q, eval.BuffQP[4].Q})
+		buff.Value[0].IsNTT = true
+		buff.Value[1].IsNTT = true
 
 		for i := logN; i < eval.params.LogN()-1; i++ {
 			eval.Automorphism(ctOut, eval.params.GaloisElementForColumnRotationBy(1<<i), buff)