Skip to content

Fix evaluation of linear functions with EvalPoly #1097

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
pascoec merged 7 commits into from
Dec 5, 2025
Merged

Fix evaluation of linear functions with EvalPoly #1097

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
7 commits
Select commit Hold shift + click to select a range
02a8e9c
Merge pull request #988 from openfheorg/dev
yspolyakov May 21, 2025
3236208
Merge pull request #1017 from openfheorg/dev
dsuponitskiy Jul 11, 2025
aa8a86e
Merge pull request #1044 from openfheorg/dev
yspolyakov Aug 18, 2025
01e2642
Merge pull request #1065 from openfheorg/dev
dsuponitskiy Oct 14, 2025
aa39198
Merge pull request #1073 from openfheorg/dev
dsuponitskiy Oct 20, 2025
6550542
Fix evaluation of linear functions with `EvalPoly`
hsanzg Dec 1, 2025
5594dd4
Merge branch 'issue1096' into linear_polys
pascoec Dec 5, 2025
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
8 changes: 4 additions & 4 deletions src/pke/lib/scheme/ckksrns/ckksrns-advancedshe.cpp
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -361,12 +361,12 @@ std::shared_ptr<seriesPowers<DCRTPoly>> AdvancedSHECKKSRNS::EvalPowers(
}

template <typename VectorDataType>
Ciphertext<DCRTPoly> internalEvalPolyLinearWithPrecomp(std::vector<Ciphertext<DCRTPoly>>& powers,
const std::vector<VectorDataType>& coefficients) {
const uint32_t k = coefficients.size() - 1;
if (k <= 1)
static inline Ciphertext<DCRTPoly> internalEvalPolyLinearWithPrecomp(std::vector<Ciphertext<DCRTPoly>>& powers,
const std::vector<VectorDataType>& coefficients) {
if (coefficients.size() < 2)
OPENFHE_THROW("The coefficients vector should contain at least 2 elements");

uint32_t k = coefficients.size() - 1;
if (!IsNotEqualZero(coefficients[k]))
OPENFHE_THROW("EvalPolyLinear: The highest-order coefficient cannot be set to 0.");

Expand Down
16 changes: 16 additions & 0 deletions src/pke/unittest/utckksrns/UnitTestCKKSrns.cpp
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -1801,6 +1801,9 @@ class UTCKKSRNS : public ::testing::TestWithParam<TEST_CASE_UTCKKSRNS> {
// x + x^2 - x^3
// low-degree function to check linear implementation
std::vector<double> coefficients5{0, 1, 1, -1};
// 1 + 2x
// linear function to check linear implementation
std::vector<double> coefficients6{1.0, 2.0};

Plaintext plaintext1 = cc->MakeCKKSPackedPlaintext(input);

Expand All @@ -1819,6 +1822,9 @@ class UTCKKSRNS : public ::testing::TestWithParam<TEST_CASE_UTCKKSRNS> {
std::vector<std::complex<double>> output5{0.625, 0.847, 0.9809999999, 0.995125, 0.990543};
Plaintext plaintextResult5 = cc->MakeCKKSPackedPlaintext(output5);

std::vector<std::complex<double>> output6{2.0, 2.4, 2.8, 2.9, 2.86};
Plaintext plaintextResult6 = cc->MakeCKKSPackedPlaintext(output6);

// Generate encryption keys
KeyPair<Element> kp = cc->KeyGen();
// Generate multiplication keys
Expand Down Expand Up @@ -1878,6 +1884,16 @@ class UTCKKSRNS : public ::testing::TestWithParam<TEST_CASE_UTCKKSRNS> {
<< " - we get: " << results5->GetCKKSPackedValue();
checkEquality(plaintextResult5->GetCKKSPackedValue(), results5->GetCKKSPackedValue(), epsHigh,
failmsg + " EvalPoly for low-degree polynomial failed: " + buffer5.str());

Ciphertext<Element> cResult6 = cc->EvalPolyLinear(ciphertext1, coefficients6);
Plaintext results6;
cc->Decrypt(kp.secretKey, cResult6, &results6);
results6->SetLength(encodedLength);
std::stringstream buffer6;
buffer6 << "should be: " << plaintextResult6->GetCKKSPackedValue()
<< " - we get: " << results6->GetCKKSPackedValue();
checkEquality(plaintextResult6->GetCKKSPackedValue(), results6->GetCKKSPackedValue(), epsHigh,
failmsg + " EvalPoly for linear polynomial failed: " + buffer6.str());
}
catch (std::exception& e) {
std::cerr << "Exception thrown from " << __func__ << "(): " << e.what() << std::endl;
Expand Down