CKKS

‘ckks’ Dialect

The CKKS dialect defines the types and operations of the CKKS cryptosystem.

CKKS ops

ckks.add (heir::ckks::AddOp)

Addition operation between ciphertexts.

Syntax:

operation ::= `ckks.add` operands attr-dict `:` qualified(type($output))

Traits: AlwaysSpeculatableImplTrait, Commutative, SameOperandsAndResultType

Interfaces: ConditionallySpeculatable, InferTypeOpInterface, NoMemoryEffect (MemoryEffectOpInterface)

Effects: MemoryEffects::Effect{}

Operands:

Results:

ckks.add_plain (heir::ckks::AddPlainOp)

Addition operation between ciphertext-plaintext.

Syntax:

operation ::= `ckks.add_plain` operands attr-dict `:`  functional-type(operands, results)

Traits: AlwaysSpeculatableImplTrait

Interfaces: ConditionallySpeculatable, InferTypeOpInterface, NoMemoryEffect (MemoryEffectOpInterface)

Effects: MemoryEffects::Effect{}

Operands:

Results:

ckks.extract (heir::ckks::ExtractOp)

Extract the i-th element of a ciphertext.

Syntax:

operation ::= `ckks.extract` operands attr-dict `:`  functional-type(operands, results)

While this operation is costly to compute in FHE, we represent it so we can implement efficient lowerings and folders.

This op can be implemented as a plaintext multiplication with a one-hot vector and a rotate into the zero-th index.

An extraction op’s input ciphertext type is asserted to have an underlying_type corresponding to a ranked tensor type, and this op’s return type is inferred to have the underlying_type corresponding to the element type of that tensor type.

Traits: SameOperandsAndResultRings

Operands:

Results:

ckks.mul (heir::ckks::MulOp)

Multiplication operation between ciphertexts.

Syntax:

operation ::= `ckks.mul` operands attr-dict `:`  functional-type(operands, results)

Traits: AlwaysSpeculatableImplTrait, Commutative, InferTypeOpAdaptor, SameOperandsAndResultRings, SameTypeOperands

Interfaces: ConditionallySpeculatable, InferTypeOpInterface, NoMemoryEffect (MemoryEffectOpInterface)

Effects: MemoryEffects::Effect{}

Operands:

Results:

ckks.mul_plain (heir::ckks::MulPlainOp)

Multiplication operation between ciphertext-plaintext.

Syntax:

operation ::= `ckks.mul_plain` operands attr-dict `:`  functional-type(operands, results)

Traits: AlwaysSpeculatableImplTrait

Interfaces: ConditionallySpeculatable, InferTypeOpInterface, NoMemoryEffect (MemoryEffectOpInterface)

Effects: MemoryEffects::Effect{}

Operands:

Results:

ckks.negate (heir::ckks::NegateOp)

Negate the coefficients of the ciphertext.

Syntax:

operation ::= `ckks.negate` operands attr-dict `:` qualified(type($output))

Traits: AlwaysSpeculatableImplTrait, Involution, SameOperandsAndResultType

Interfaces: ConditionallySpeculatable, InferTypeOpInterface, NoMemoryEffect (MemoryEffectOpInterface)

Effects: MemoryEffects::Effect{}

Operands:

Results:

ckks.relinearize (heir::ckks::RelinearizeOp)

Relinearize the ciphertext.

Syntax:

operation ::= `ckks.relinearize` operands attr-dict `:` qualified(type($input)) `->` qualified(type($output))

This op takes integer array attributes from_basis and to_basis that are used to indicate the key basis from which and to which the ciphertext is encrypted against. A ciphertext is canonically encrypted against key basis (1, s). After a multiplication, its size will increase and the basis will be (1, s, s^2). The array that represents the key basis is constructed by listing the powers of s at each position of the array. For example, (1, s, s^2) corresponds to [0, 1, 2], while (1, s^2) corresponds to [0, 2].

Traits: AlwaysSpeculatableImplTrait, InferTypeOpAdaptor, SameOperandsAndResultRings

Interfaces: ConditionallySpeculatable, InferTypeOpInterface, NoMemoryEffect (MemoryEffectOpInterface)

Effects: MemoryEffects::Effect{}

Attributes:

Operands:

Results:

ckks.rescale (heir::ckks::RescaleOp)

Rescales the ciphertext, which is the CKKS version of modulus switching in BGV/BFV.

Syntax:

operation ::= `ckks.rescale` operands attr-dict `:` qualified(type($input)) `->` qualified(type($output))

Traits: AlwaysSpeculatableImplTrait

Interfaces: ConditionallySpeculatable, NoMemoryEffect (MemoryEffectOpInterface)

Effects: MemoryEffects::Effect{}

Attributes:

Operands:

Results:

ckks.rotate (heir::ckks::RotateOp)

Rotate the coefficients of the ciphertext using a Galois automorphism.

Syntax:

operation ::= `ckks.rotate` operands attr-dict `:` qualified(type($input))

Traits: AlwaysSpeculatableImplTrait

Interfaces: ConditionallySpeculatable, InferTypeOpInterface, NoMemoryEffect (MemoryEffectOpInterface)

Effects: MemoryEffects::Effect{}

Attributes:

Operands:

Results:

ckks.sub (heir::ckks::SubOp)

Subtraction operation between ciphertexts.

Syntax:

operation ::= `ckks.sub` operands attr-dict `:` qualified(type($output))

Traits: SameOperandsAndResultType

Interfaces: InferTypeOpInterface

Operands:

Results:

ckks.sub_plain (heir::ckks::SubPlainOp)

Subtraction operation between ciphertext-plaintext.

Syntax:

operation ::= `ckks.sub_plain` operands attr-dict `:`  functional-type(operands, results)

Traits: AlwaysSpeculatableImplTrait

Interfaces: ConditionallySpeculatable, InferTypeOpInterface, NoMemoryEffect (MemoryEffectOpInterface)

Effects: MemoryEffects::Effect{}

Operands:

Results: