Documentation
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Overview ¶
Package crypto provides homomorphic encryption operations using Lattigo CKKS scheme. CKKS is ideal for approximate arithmetic on encrypted real numbers.
Index ¶
- func NewParameters() (hefloat.Parameters, error)
- func NormalizeVector(vector []float64) []float64
- type Engine
- func (e *Engine) DecryptBatchScalars(ct *rlwe.Ciphertext, numCentroids, dimension int) ([]float64, error)
- func (e *Engine) DecryptScalar(ct *rlwe.Ciphertext) (float64, error)
- func (e *Engine) DecryptVector(ct *rlwe.Ciphertext, length int) ([]float64, error)
- func (e *Engine) DeserializeCiphertext(data []byte) (*rlwe.Ciphertext, error)
- func (e *Engine) EncryptVector(vector []float64) (*rlwe.Ciphertext, error)
- func (e *Engine) GetEncoder() *hefloat.Encoder
- func (e *Engine) GetParams() hefloat.Parameters
- func (e *Engine) GetPublicKeyBytes() ([]byte, error)
- func (e *Engine) HomomorphicBatchDotProduct(encPackedQuery *rlwe.Ciphertext, packedCentroids *rlwe.Plaintext, ...) (*rlwe.Ciphertext, error)
- func (e *Engine) HomomorphicDotProduct(encQuery *rlwe.Ciphertext, vector []float64) (*rlwe.Ciphertext, error)
- func (e *Engine) HomomorphicDotProductCached(encQuery *rlwe.Ciphertext, encodedVector *rlwe.Plaintext) (*rlwe.Ciphertext, error)
- func (e *Engine) SerializeCiphertext(ct *rlwe.Ciphertext) ([]byte, error)
- type EnginePool
- func (p *EnginePool) Acquire() *Engine
- func (p *EnginePool) DecryptBatchScalars(ct *rlwe.Ciphertext, numCentroids, dimension int) ([]float64, error)
- func (p *EnginePool) DecryptScalar(ct *rlwe.Ciphertext) (float64, error)
- func (p *EnginePool) EncryptVector(vector []float64) (*rlwe.Ciphertext, error)
- func (p *EnginePool) GetEncoder() *hefloat.Encoder
- func (p *EnginePool) GetParams() hefloat.Parameters
- func (p *EnginePool) GetPrimaryEngine() *Engine
- func (p *EnginePool) HomomorphicBatchDotProduct(encPackedQuery *rlwe.Ciphertext, packedCentroids *rlwe.Plaintext, ...) (*rlwe.Ciphertext, error)
- func (p *EnginePool) Release(e *Engine)
- func (p *EnginePool) Size() int
Constants ¶
This section is empty.
Variables ¶
This section is empty.
Functions ¶
func NewParameters ¶
func NewParameters() (hefloat.Parameters, error)
NewParameters creates CKKS parameters optimized for vector dot products. Uses 128-bit security with LogN=14 supporting vectors up to 8192 dimensions.
func NormalizeVector ¶
NormalizeVector normalizes a vector to unit length
Types ¶
type Engine ¶
type Engine struct {
// contains filtered or unexported fields
}
Engine provides homomorphic encryption operations using CKKS scheme. CKKS allows approximate arithmetic on encrypted floating-point numbers, which is ideal for computing dot products for similarity search.
func NewClientEngine ¶
NewClientEngine creates an encryption engine for client-side operations. Generates a new key pair for encryption/decryption.
func NewServerEngine ¶
NewServerEngine creates an encryption engine for server-side operations. Does not have access to the secret key - can only perform homomorphic operations.
func (*Engine) DecryptBatchScalars ¶
func (e *Engine) DecryptBatchScalars(ct *rlwe.Ciphertext, numCentroids, dimension int) ([]float64, error)
DecryptBatchScalars decrypts and extracts multiple dot product results from a batch operation. Results are at positions [0, dim, 2*dim, ...] in the decrypted slots.
func (*Engine) DecryptScalar ¶
func (e *Engine) DecryptScalar(ct *rlwe.Ciphertext) (float64, error)
DecryptScalar decrypts a ciphertext containing a single scalar value (dot product result).
func (*Engine) DecryptVector ¶
DecryptVector decrypts a ciphertext back to a float64 vector.
func (*Engine) DeserializeCiphertext ¶
func (e *Engine) DeserializeCiphertext(data []byte) (*rlwe.Ciphertext, error)
DeserializeCiphertext deserializes bytes to a ciphertext
func (*Engine) EncryptVector ¶
func (e *Engine) EncryptVector(vector []float64) (*rlwe.Ciphertext, error)
EncryptVector encrypts a float64 vector using CKKS. Values should be normalized to [-1, 1] range for best precision. CKKS directly handles floating-point values without offset encoding.
func (*Engine) GetEncoder ¶
GetEncoder returns the HE encoder for external caching purposes.
func (*Engine) GetParams ¶
func (e *Engine) GetParams() hefloat.Parameters
GetParams returns the CKKS parameters
func (*Engine) GetPublicKeyBytes ¶
GetPublicKeyBytes returns the serialized public key for distribution
func (*Engine) HomomorphicBatchDotProduct ¶
func (e *Engine) HomomorphicBatchDotProduct(encPackedQuery *rlwe.Ciphertext, packedCentroids *rlwe.Plaintext, numCentroids, dimension int) (*rlwe.Ciphertext, error)
HomomorphicBatchDotProduct computes multiple dot products in a single HE operation. The query should be packed (replicated across slot segments) to match packed centroids. Returns encrypted result where each dimension-sized segment contains one dot product.
Layout after operation:
- slots[0..dim-1]: components of dot(q, c0)
- slots[dim..2*dim-1]: components of dot(q, c1)
- etc.
After partial sum within each segment:
- slots[0]: dot(q, c0)
- slots[dim]: dot(q, c1)
- etc.
func (*Engine) HomomorphicDotProduct ¶
func (e *Engine) HomomorphicDotProduct(encQuery *rlwe.Ciphertext, vector []float64) (*rlwe.Ciphertext, error)
HomomorphicDotProduct computes E(q · v) from E(q) and plaintext v. This is the core operation for privacy-preserving similarity search. Returns encrypted dot product that only the client can decrypt. Note: Uses full lock because Lattigo evaluator is not thread-safe.
func (*Engine) HomomorphicDotProductCached ¶
func (e *Engine) HomomorphicDotProductCached(encQuery *rlwe.Ciphertext, encodedVector *rlwe.Plaintext) (*rlwe.Ciphertext, error)
HomomorphicDotProductCached computes E(q · v) using a pre-encoded plaintext. This is faster than HomomorphicDotProduct when centroids are cached as plaintexts. Note: Uses full lock because Lattigo evaluator is not thread-safe.
func (*Engine) SerializeCiphertext ¶
func (e *Engine) SerializeCiphertext(ct *rlwe.Ciphertext) ([]byte, error)
SerializeCiphertext serializes a ciphertext to bytes for transmission
type EnginePool ¶
type EnginePool struct {
// contains filtered or unexported fields
}
EnginePool manages a pool of HE engines for parallel operations. Each engine has its own evaluator (not thread-safe), but shares keys. This allows parallel HE operations without the serialization bottleneck.
func NewEnginePool ¶
func NewEnginePool(n int) (*EnginePool, error)
NewEnginePool creates a pool of n HE engines. All engines share the same keys but have independent evaluators. Recommended: n = runtime.NumCPU() for optimal parallelism.
func (*EnginePool) Acquire ¶
func (p *EnginePool) Acquire() *Engine
Acquire gets an engine from the pool. Blocks if none available. The caller MUST call Release when done.
func (*EnginePool) DecryptBatchScalars ¶
func (p *EnginePool) DecryptBatchScalars(ct *rlwe.Ciphertext, numCentroids, dimension int) ([]float64, error)
DecryptBatchScalars decrypts and extracts multiple dot product results.
func (*EnginePool) DecryptScalar ¶
func (p *EnginePool) DecryptScalar(ct *rlwe.Ciphertext) (float64, error)
DecryptScalar decrypts a scalar result using the primary engine.
func (*EnginePool) EncryptVector ¶
func (p *EnginePool) EncryptVector(vector []float64) (*rlwe.Ciphertext, error)
EncryptVector encrypts a vector using the primary engine. This is typically called once per query, so serialization is acceptable.
func (*EnginePool) GetEncoder ¶
func (p *EnginePool) GetEncoder() *hefloat.Encoder
GetEncoder returns an encoder (from the primary engine). Note: Encoder may not be thread-safe for encoding, but is fine for reading params.
func (*EnginePool) GetParams ¶
func (p *EnginePool) GetParams() hefloat.Parameters
GetParams returns the CKKS parameters (same for all engines).
func (*EnginePool) GetPrimaryEngine ¶
func (p *EnginePool) GetPrimaryEngine() *Engine
GetPrimaryEngine returns the first engine (useful for encryption/decryption).
func (*EnginePool) HomomorphicBatchDotProduct ¶
func (p *EnginePool) HomomorphicBatchDotProduct(encPackedQuery *rlwe.Ciphertext, packedCentroids *rlwe.Plaintext, numCentroids, dimension int) (*rlwe.Ciphertext, error)
HomomorphicBatchDotProduct computes multiple dot products using SIMD.
func (*EnginePool) Release ¶
func (p *EnginePool) Release(e *Engine)
Release returns an engine to the pool.
func (*EnginePool) Size ¶
func (p *EnginePool) Size() int
Size returns the number of engines in the pool.
Source Files