changelog + change name partialtrace

CHANGELOG.md

@@ -3,7 +3,7 @@ All notable changes to this library are documented in this file.
 
 ## [6.x.x] - 16.12.2024
 - Refactoring of the InnerSum methods: 
-  - `rlwe.Evaluator.InnerSum` has been replaced by `rlwe.Evaluator.PartialTrace`
+  - `rlwe.Evaluator.InnerSum` has been replaced by `rlwe.Evaluator.PartialTracesSum`, which applies the automorphisms that correspond to rotations at the scheme level (and sum the results).
   - Introduction of the `bgv.Evaluator.InnerSum` and `ckks.Evaluator.InnerSum` methods, which have the same behaviour as the old `InnerSum` method for parameters `n` and `batchSize` s.t. `0 < n*batchSize <= ctIn.Slots()` divides the number of slots. Parameters not satisfying these conditions are rejected.
   - Introduction of the `bgv.Evaluator.RotateAndAdd` and `ckks.Evaluator.RotateAndAdd` methods, which have the same behaviour as the old `InnerSum` method for all parameters. 
 

core/rlwe/inner_sum.go

@@ -144,10 +144,11 @@ func GaloisElementsForTrace(params ParameterProvider, logN int) (galEls []uint64
 	return
 }
 
-// PartialTrace applies a partial trace on the input ciphertext with the automorphisms phi(i*offset, X), 0 <= i < n, where phi(k, X): X -> X^{5^k}
+// PartialTracesSum applies a set of automorphisms on the input ciphertext and sum the results.
+// The automorphisms are of the form phi(i*offset, X), 0 <= i < n, where phi(k, X): X -> X^{5^k}
 // i.e. opOut = \sum_{i = 0}^{n-1} phi(i*offset, ctIn).
 // At the scheme level, this function is used to perform inner sums or efficiently replicate slots.
-func (eval Evaluator) PartialTrace(ctIn *Ciphertext, offset, n int, opOut *Ciphertext) (err error) {
+func (eval Evaluator) PartialTracesSum(ctIn *Ciphertext, offset, n int, opOut *Ciphertext) (err error) {
 	if n == 0 || offset == 0 {
 		return fmt.Errorf("partialtrace: invalid parameter (n = 0 or batchSize = 0)")
 	}
@@ -473,7 +474,7 @@ func GaloisElementsForInnerSum(params ParameterProvider, batch, n int) (galEls [
 // two consecutive sub-vectors to replicate.
 // This method is faster than Replicate when the number of rotations is large and it uses log2(n) + HW(n) instead of n.
 func (eval Evaluator) Replicate(ctIn *Ciphertext, batchSize, n int, opOut *Ciphertext) (err error) {
-	return eval.PartialTrace(ctIn, -batchSize, n, opOut)
+	return eval.PartialTracesSum(ctIn, -batchSize, n, opOut)
 }
 
 // GaloisElementsForReplicate returns the list of Galois elements necessary to perform the

core/rlwe/rlwe_test.go

@@ -1103,7 +1103,7 @@ func testSlotOperations(tc *TestContext, level, bpw2 int, t *testing.T) {
 		// Galois Keys
 		evk := NewMemEvaluationKeySet(nil, kgen.GenGaloisKeysNew(GaloisElementsForInnerSum(params, batch, n), sk)...)
 
-		require.NoError(t, eval.WithKey(evk).PartialTrace(ct, batch, n, ct))
+		require.NoError(t, eval.WithKey(evk).PartialTracesSum(ct, batch, n, ct))
 
 		dec.Decrypt(ct, pt)
 

schemes/bgv/evaluator.go

@@ -1544,7 +1544,7 @@ func (eval Evaluator) InnerSum(ctIn *rlwe.Ciphertext, batchSize, n int, opOut *r
 			return
 		}
 
-		if err = eval.Evaluator.PartialTrace(ctIn, batchSize, n/2, opOut); err != nil {
+		if err = eval.Evaluator.PartialTracesSum(ctIn, batchSize, n/2, opOut); err != nil {
 			return
 		}
 
@@ -1561,7 +1561,7 @@ func (eval Evaluator) InnerSum(ctIn *rlwe.Ciphertext, batchSize, n int, opOut *r
 		return
 	}
 
-	err = eval.Evaluator.PartialTrace(ctIn, batchSize, n, opOut)
+	err = eval.Evaluator.PartialTracesSum(ctIn, batchSize, n, opOut)
 	return
 }
 
@@ -1581,7 +1581,7 @@ func (eval Evaluator) InnerSum(ctIn *rlwe.Ciphertext, batchSize, n int, opOut *r
 //
 // Calling RotateAndAdd(ctIn, 1, n, opOut) can be used to compute the inner sum of the first n slots of a plaintext.
 func (eval Evaluator) RotateAndAdd(ctIn *rlwe.Ciphertext, batchSize, n int, opOut *rlwe.Ciphertext) (err error) {
-	err = eval.Evaluator.PartialTrace(ctIn, batchSize, n, opOut)
+	err = eval.Evaluator.PartialTracesSum(ctIn, batchSize, n, opOut)
 	return
 }
 

schemes/ckks/evaluator.go

@@ -1294,7 +1294,7 @@ func (eval Evaluator) InnerSum(ctIn *rlwe.Ciphertext, batchSize, n int, opOut *r
 	if l&(l-1) != 0 {
 		return fmt.Errorf("innersum: invalid parameters (n*batchSize=%d does not divide #slots=%d)", l, N)
 	}
-	err = eval.Evaluator.PartialTrace(ctIn, batchSize, n, opOut)
+	err = eval.Evaluator.PartialTracesSum(ctIn, batchSize, n, opOut)
 	return
 }
 
@@ -1312,7 +1312,7 @@ func (eval Evaluator) InnerSum(ctIn *rlwe.Ciphertext, batchSize, n int, opOut *r
 //
 // Calling RotateAndAdd(ctIn, 1, n, opOut) can be used to compute the inner sum of the first n slots of a plaintext.
 func (eval Evaluator) RotateAndAdd(ctIn *rlwe.Ciphertext, batchSize, n int, opOut *rlwe.Ciphertext) (err error) {
-	err = eval.Evaluator.PartialTrace(ctIn, batchSize, n, opOut)
+	err = eval.Evaluator.PartialTracesSum(ctIn, batchSize, n, opOut)
 	return
 }