concrete-optimizer is a tool that selects appropriate cryptographic parameters for a given fully homomorphic encryption (FHE) computation. These parameters have an impact on the security, correctness, and efficiency of the computation.

The computation is guaranteed to be secure with the given level of security (see here for details) which is typically 128 bits. The correctness of the computation is guaranteed up to a given failure probability. A surrogate of the execution time is minimized which allows for efficient FHE computation.

The cryptographic parameters are degrees of freedom in the FHE algorithms (bootstrapping, keyswitching, etc.) that need to be fixed. The search space for possible crypto-parameters is finite but extremely large. The role of the optimizer is to quickly find the most efficient crypto-parameters possible while guaranteeing security and correctness.

Security, Correctness, and Efficiency

Security

The security level is chosen by the user. We typically operate at a fixed security level, such as 128 bits, to ensure that there is never a trade-off between security and efficiency. This constraint imposes a minimum amount of noise in all ciphertexts.

An independent public research tool, the lattice estimator, is used to estimate the security level. The lattice estimator is maintained by FHE experts. For a given set of crypto-parameters, this tool considers all possible attacks and returns a security level.

For each security level, a parameter curve of the appropriate minimal error level is pre-computed using the lattice estimator, and is used as an input to the optimizer. Learn more about the parameter curves here.

Correctness

Correctness decreases as the level of noise increases. Noise accumulates during homomorphic computation until it is actively reduced via bootstrapping. Too much noise can lead to the result of a computation being inaccurate or completely incorrect.

Before optimization, we compute a noise bound that guarantees a given error level (under the assumption that noise growth is correctly managed via bootstrapping). The noise growth depends on a critical quantity: the 2-norm of any dot product (or equivalent) present in the calculus. This 2-norm changes the scale of the noise, so we must reduce it sufficiently for the next dot product operation whenever we reduce the noise.

The user can control error probability in two ways: via the PBS error probability and the global error probability.

The PBS error probability controls correctness locally (i.e., represents the error probability of a single PBS operation), while the global error probability focuses on the overall computation result (i.e., represents the error probability of the entire computation). These probabilities are related, and choosing which one to use may depend on the specific use case.

Efficiency

Efficiency decreases as more precision is required, e.g. 7-bits versus 8-bits. The larger the 2-norm is, the bigger the noise will be after a dot product. To remain below the noise bound, we must ensure that the inputs to the dot product have a sufficiently small noise level. The smaller this noise is, the slower the previous bootstrapping will be. Therefore, the larger the 2norm is, the slower the computation will be.

How are the parameters optimized

The optimization prioritizes security and correctness. This means that the security level (or the probability of correctness) could, in practice, be a bit higher than the level which is requested by the user.

In the simplest case, the optimizer performs an exhaustive search in the full parameter space and selects the best solution. While the space to explore is huge, exact lower bound cuts are used to avoid exploring regions which are guaranteed to not contain an optimal point. This makes the process both fast and exhaustive. This case is called mono-parameter, where all parameters are shared by the whole computation graph.

In more complex cases, the optimizer iteratively performs an exhaustive search, with lower bound cuts in a wide subspace of the full parameter space, until it converges to a locally optimal solution. Since the wide subspace is large and multi-dimensional, it should not be trapped in a poor locally optimal solution. The more complex case is called multi-parameter, where different calculus operations have tailored parameters.

How can I determine, understand, and explore crypto-parameters

One can have a look at reference crypto-parameters for each security level (but for a given correctness). This provides insight between the calcululs content (i.e. maximum precision, maximum dot 2-norm, etc.,) and the cost.

Then one can manually explore crypto-parameters space using a CLI tool.

Citing

If you use this tool in your work, please cite:

Bergerat, Loris and Boudi, Anas and Bourgerie, Quentin and Chillotti, Ilaria and Ligier, Damien and Orfila Jean-Baptiste and Tap, Samuel, Parameter Optimization and Larger Precision for (T)FHE, Journal of Cryptology, 2023, Volume 36

A pre-print is available as Cryptology ePrint Archive Paper 2022/704

High Level Fully Homomorphic Encryption dialect A dialect for representation of high level operation on fully homomorphic ciphertext.

Operation definition

FHE.add_eint_int (::mlir::concretelang::FHE::AddEintIntOp)

Adds an encrypted integer and a clear integer

The clear integer must have at most one more bit than the encrypted integer and the result must have the same width and the same signedness as the encrypted integer.

Example:

// ok
"FHE.add_eint_int"(%a, %i) : (!FHE.eint<2>, i3) -> !FHE.eint<2>
"FHE.add_eint_int"(%a, %i) : (!FHE.esint<2>, i3) -> !FHE.esint<2>

// error
"FHE.add_eint_int"(%a, %i) : (!FHE.eint<2>, i4) -> !FHE.eint<2>
"FHE.add_eint_int"(%a, %i) : (!FHE.eint<2>, i3) -> !FHE.eint<3>
"FHE.add_eint_int"(%a, %i) : (!FHE.eint<2>, i3) -> !FHE.esint<2>

Traits: AlwaysSpeculatableImplTrait

Interfaces: Binary, BinaryEintInt, ConditionallySpeculatable, NoMemoryEffect (MemoryEffectOpInterface)

Effects: MemoryEffects::Effect{}

Operands:

Results:

FHE.add_eint (::mlir::concretelang::FHE::AddEintOp)

Adds two encrypted integers

The encrypted integers and the result must have the same width and the same signedness.

Example:

// ok
"FHE.add_eint"(%a, %b): (!FHE.eint<2>, !FHE.eint<2>) -> (!FHE.eint<2>)
"FHE.add_eint"(%a, %b): (!FHE.esint<2>, !FHE.esint<2>) -> (!FHE.esint<2>)

// error
"FHE.add_eint"(%a, %b): (!FHE.eint<2>, !FHE.eint<3>) -> (!FHE.eint<2>)
"FHE.add_eint"(%a, %b): (!FHE.eint<2>, !FHE.eint<2>) -> (!FHE.eint<3>)
"FHE.add_eint"(%a, %b): (!FHE.eint<2>, !FHE.eint<2>) -> (!FHE.esint<2>)
"FHE.add_eint"(%a, %b): (!FHE.esint<2>, !FHE.eint<2>) -> (!FHE.eint<2>)

Traits: AlwaysSpeculatableImplTrait

Interfaces: BinaryEint, ConditionallySpeculatable, NoMemoryEffect (MemoryEffectOpInterface)

Effects: MemoryEffects::Effect{}

Operands:

Results:

FHE.apply_lookup_table (::mlir::concretelang::FHE::ApplyLookupTableEintOp)

Applies a clear lookup table to an encrypted integer

The width of the result can be different than the width of the operand. The lookup table must be a tensor of size 2^p where p is the width of the encrypted integer.

Example:

// ok
"FHE.apply_lookup_table"(%a, %lut): (!FHE.eint<2>, tensor<4xi64>) -> (!FHE.eint<2>)
"FHE.apply_lookup_table"(%a, %lut): (!FHE.eint<2>, tensor<4xi64>) -> (!FHE.eint<3>)
"FHE.apply_lookup_table"(%a, %lut): (!FHE.eint<3>, tensor<4xi64>) -> (!FHE.eint<2>)

// error
"FHE.apply_lookup_table"(%a, %lut): (!FHE.eint<2>, tensor<8xi64>) -> (!FHE.eint<2>)

Traits: AlwaysSpeculatableImplTrait

Interfaces: ConditionallySpeculatable, ConstantNoise, NoMemoryEffect (MemoryEffectOpInterface)

Effects: MemoryEffects::Effect{}

Operands:

Results:

FHE.and (::mlir::concretelang::FHE::BoolAndOp)

Applies an AND gate to two encrypted boolean values

Example:

"FHE.and"(%a, %b): (!FHE.ebool, !FHE.ebool) -> (!FHE.ebool)

Traits: AlwaysSpeculatableImplTrait

Interfaces: ConditionallySpeculatable, NoMemoryEffect (MemoryEffectOpInterface)

Effects: MemoryEffects::Effect{}

Operands:

Results:

FHE.nand (::mlir::concretelang::FHE::BoolNandOp)

Applies a NAND gate to two encrypted boolean values

Example:

"FHE.nand"(%a, %b): (!FHE.ebool, !FHE.ebool) -> (!FHE.ebool)

Traits: AlwaysSpeculatableImplTrait

Interfaces: ConditionallySpeculatable, NoMemoryEffect (MemoryEffectOpInterface)

Effects: MemoryEffects::Effect{}

Operands:

Results:

FHE.not (::mlir::concretelang::FHE::BoolNotOp)

Applies a NOT gate to an encrypted boolean value

Example:

"FHE.not"(%a): (!FHE.ebool) -> (!FHE.ebool)

Traits: AlwaysSpeculatableImplTrait

Interfaces: ConditionallySpeculatable, NoMemoryEffect (MemoryEffectOpInterface), UnaryEint

Effects: MemoryEffects::Effect{}

Operands:

Results:

FHE.or (::mlir::concretelang::FHE::BoolOrOp)

Applies an OR gate to two encrypted boolean values

Example:

"FHE.or"(%a, %b): (!FHE.ebool, !FHE.ebool) -> (!FHE.ebool)

Traits: AlwaysSpeculatableImplTrait

Interfaces: ConditionallySpeculatable, NoMemoryEffect (MemoryEffectOpInterface)

Effects: MemoryEffects::Effect{}

Operands:

Results:

FHE.xor (::mlir::concretelang::FHE::BoolXorOp)

Applies an XOR gate to two encrypted boolean values

Example:

"FHE.xor"(%a, %b): (!FHE.ebool, !FHE.ebool) -> (!FHE.ebool)

Traits: AlwaysSpeculatableImplTrait

Interfaces: ConditionallySpeculatable, NoMemoryEffect (MemoryEffectOpInterface)

Effects: MemoryEffects::Effect{}

Operands:

Results:

FHE.from_bool (::mlir::concretelang::FHE::FromBoolOp)

Cast a boolean to an unsigned integer

Examples:

"FHE.from_bool"(%x) : (!FHE.ebool) -> !FHE.eint<1>
"FHE.from_bool"(%x) : (!FHE.ebool) -> !FHE.eint<2>
"FHE.from_bool"(%x) : (!FHE.ebool) -> !FHE.eint<4>

Traits: AlwaysSpeculatableImplTrait

Interfaces: ConditionallySpeculatable, NoMemoryEffect (MemoryEffectOpInterface), UnaryEint

Effects: MemoryEffects::Effect{}

Operands:

Results:

FHE.gen_gate (::mlir::concretelang::FHE::GenGateOp)

Applies a truth table based on two boolean inputs

Truth table must be a tensor of four boolean values.

Example:

// ok
"FHE.gen_gate"(%a, %b, %ttable): (!FHE.ebool, !FHE.ebool, tensor<4xi64>) -> (!FHE.ebool)

// error
"FHE.gen_gate"(%a, %b, %ttable): (!FHE.ebool, !FHE.ebool, tensor<7xi64>) -> (!FHE.ebool)

Traits: AlwaysSpeculatableImplTrait

Interfaces: ConditionallySpeculatable, NoMemoryEffect (MemoryEffectOpInterface)

Effects: MemoryEffects::Effect{}

Operands:

Results:

FHE.max_eint (::mlir::concretelang::FHE::MaxEintOp)

Retrieve the maximum of two encrypted integers.

Retrieve the maximum of two encrypted integers using the formula, 'max(x, y) == max(x - y, 0) + y'. The input and output types should be the same.

If `x - y`` inside the max overflows or underflows, the behavior is undefined. To support the full range, you should increase the bit-width by 1 manually.

Example:

// ok
"FHE.max_eint"(%x, %y) : (!FHE.eint<2>, !FHE.eint<2>) -> !FHE.eint<2>
"FHE.max_eint"(%x, %y) : (!FHE.esint<3>, !FHE.esint<3>) -> !FHE.esint<3>

// error
"FHE.max_eint"(%x, %y) : (!FHE.eint<2>, !FHE.eint<3>) -> !FHE.eint<2>
"FHE.max_eint"(%x, %y) : (!FHE.eint<2>, !FHE.eint<2>) -> !FHE.esint<2>
"FHE.max_eint"(%x, %y) : (!FHE.esint<2>, !FHE.eint<2>) -> !FHE.eint<2>

Traits: AlwaysSpeculatableImplTrait

Interfaces: BinaryEint, ConditionallySpeculatable, NoMemoryEffect (MemoryEffectOpInterface)

Effects: MemoryEffects::Effect{}

Operands:

Results:

FHE.mul_eint_int (::mlir::concretelang::FHE::MulEintIntOp)

Multiply an encrypted integer with a clear integer

The clear integer must have one more bit than the encrypted integer and the result must have the same width and the same signedness as the encrypted integer.

Example:

// ok
"FHE.mul_eint_int"(%a, %i) : (!FHE.eint<2>, i3) -> !FHE.eint<2>
"FHE.mul_eint_int"(%a, %i) : (!FHE.esint<2>, i3) -> !FHE.esint<2>

// error
"FHE.mul_eint_int"(%a, %i) : (!FHE.eint<2>, i4) -> !FHE.eint<2>
"FHE.mul_eint_int"(%a, %i) : (!FHE.eint<2>, i3) -> !FHE.eint<3>
"FHE.mul_eint_int"(%a, %i) : (!FHE.eint<2>, i3) -> !FHE.esint<2>

Traits: AlwaysSpeculatableImplTrait

Interfaces: Binary, BinaryEintInt, ConditionallySpeculatable, NoMemoryEffect (MemoryEffectOpInterface)

Effects: MemoryEffects::Effect{}

Operands:

Results:

FHE.mul_eint (::mlir::concretelang::FHE::MulEintOp)

Multiplies two encrypted integers

The encrypted integers and the result must have the same width and signedness. Also, due to the current implementation, one supplementary bit of width must be provided, in addition to the number of bits needed to encode the largest output value.

Example:

// ok
"FHE.mul_eint"(%a, %b): (!FHE.eint<2>, !FHE.eint<2>) -> (!FHE.eint<2>)
"FHE.mul_eint"(%a, %b): (!FHE.eint<3>, !FHE.eint<3>) -> (!FHE.eint<3>)
"FHE.mul_eint"(%a, %b): (!FHE.esint<3>, !FHE.esint<3>) -> (!FHE.esint<3>)

// error
"FHE.mul_eint"(%a, %b): (!FHE.eint<2>, !FHE.eint<3>) -> (!FHE.eint<2>)
"FHE.mul_eint"(%a, %b): (!FHE.eint<2>, !FHE.eint<2>) -> (!FHE.eint<3>)
"FHE.mul_eint"(%a, %b): (!FHE.eint<2>, !FHE.eint<2>) -> (!FHE.esint<2>)
"FHE.mul_eint"(%a, %b): (!FHE.esint<2>, !FHE.eint<2>) -> (!FHE.eint<2>)

Traits: AlwaysSpeculatableImplTrait

Interfaces: BinaryEint, ConditionallySpeculatable, NoMemoryEffect (MemoryEffectOpInterface)

Effects: MemoryEffects::Effect{}

Operands:

Results:

FHE.mux (::mlir::concretelang::FHE::MuxOp)

Multiplexer for two encrypted boolean inputs, based on an encrypted condition

Example:

"FHE.mux"(%cond, %c1, %c2): (!FHE.ebool, !FHE.ebool, !FHE.ebool) -> (!FHE.ebool)

Traits: AlwaysSpeculatableImplTrait

Interfaces: ConditionallySpeculatable, NoMemoryEffect (MemoryEffectOpInterface)

Effects: MemoryEffects::Effect{}

Operands:

Results:

FHE.neg_eint (::mlir::concretelang::FHE::NegEintOp)

Negates an encrypted integer

The result must have the same width and the same signedness as the encrypted integer.

Example:

// ok
"FHE.neg_eint"(%a): (!FHE.eint<2>) -> (!FHE.eint<2>)
"FHE.neg_eint"(%a): (!FHE.esint<2>) -> (!FHE.esint<2>)

// error
"FHE.neg_eint"(%a): (!FHE.eint<2>) -> (!FHE.eint<3>)
"FHE.neg_eint"(%a): (!FHE.eint<2>) -> (!FHE.esint<2>)

Traits: AlwaysSpeculatableImplTrait

Interfaces: ConditionallySpeculatable, NoMemoryEffect (MemoryEffectOpInterface), UnaryEint

Effects: MemoryEffects::Effect{}

Operands:

Results:

FHE.round (::mlir::concretelang::FHE::RoundEintOp)

Rounds a ciphertext to a smaller precision.

Assuming a ciphertext whose message is implemented over p bits, this operation rounds it to fit to q bits with p>q.

Example:

 // ok
 "FHE.round"(%a): (!FHE.eint<6>) -> (!FHE.eint<5>)
 "FHE.round"(%a): (!FHE.eint<5>) -> (!FHE.eint<3>)
 "FHE.round"(%a): (!FHE.eint<3>) -> (!FHE.eint<2>)
 "FHE.round"(%a): (!FHE.esint<3>) -> (!FHE.esint<2>)

// error
 "FHE.round"(%a): (!FHE.eint<6>) -> (!FHE.eint<6>)
 "FHE.round"(%a): (!FHE.eint<4>) -> (!FHE.eint<5>)
 "FHE.round"(%a): (!FHE.eint<4>) -> (!FHE.esint<5>)

Traits: AlwaysSpeculatableImplTrait

Interfaces: ConditionallySpeculatable, NoMemoryEffect (MemoryEffectOpInterface), UnaryEint

Effects: MemoryEffects::Effect{}

Operands:

Results:

FHE.sub_eint_int (::mlir::concretelang::FHE::SubEintIntOp)

Subtract a clear integer from an encrypted integer

The clear integer must have one more bit than the encrypted integer and the result must have the same width and the same signedness as the encrypted integer.

Example:

// ok
"FHE.sub_eint_int"(%i, %a) : (!FHE.eint<2>, i3) -> !FHE.eint<2>
"FHE.sub_eint_int"(%i, %a) : (!FHE.esint<2>, i3) -> !FHE.esint<2>

// error
"FHE.sub_eint_int"(%i, %a) : (!FHE.eint<2>, i4) -> !FHE.eint<2>
"FHE.sub_eint_int"(%i, %a) : (!FHE.eint<2>, i3) -> !FHE.eint<3>
"FHE.sub_eint_int"(%i, %a) : (!FHE.eint<2>, i3) -> !FHE.esint<2>

Traits: AlwaysSpeculatableImplTrait

Interfaces: Binary, BinaryEintInt, ConditionallySpeculatable, NoMemoryEffect (MemoryEffectOpInterface)

Effects: MemoryEffects::Effect{}

Operands:

Results:

FHE.sub_eint (::mlir::concretelang::FHE::SubEintOp)

Subtract an encrypted integer from an encrypted integer

The encrypted integers and the result must have the same width and the same signedness.

Example:

// ok
"FHE.sub_eint"(%a, %b): (!FHE.eint<2>, !FHE.eint<2>) -> (!FHE.eint<2>)
"FHE.sub_eint"(%a, %b): (!FHE.esint<2>, !FHE.esint<2>) -> (!FHE.esint<2>)

// error
"FHE.sub_eint"(%a, %b): (!FHE.eint<2>, !FHE.eint<3>) -> (!FHE.eint<2>)
"FHE.sub_eint"(%a, %b): (!FHE.eint<2>, !FHE.eint<2>) -> (!FHE.eint<3>)
"FHE.sub_eint"(%a, %b): (!FHE.eint<2>, !FHE.esint<2>) -> (!FHE.esint<2>)
"FHE.sub_eint"(%a, %b): (!FHE.eint<2>, !FHE.eint<2>) -> (!FHE.esint<2>)

Traits: AlwaysSpeculatableImplTrait

Interfaces: BinaryEint, ConditionallySpeculatable, NoMemoryEffect (MemoryEffectOpInterface)

Effects: MemoryEffects::Effect{}

Operands:

Results:

FHE.sub_int_eint (::mlir::concretelang::FHE::SubIntEintOp)

Subtract an encrypted integer from a clear integer

The clear integer must have one more bit than the encrypted integer and the result must have the same width and the same signedness as the encrypted integer.

Example:

// ok
"FHE.sub_int_eint"(%i, %a) : (i3, !FHE.eint<2>) -> !FHE.eint<2>
"FHE.sub_int_eint"(%i, %a) : (i3, !FHE.esint<2>) -> !FHE.esint<2>

// error
"FHE.sub_int_eint"(%i, %a) : (i4, !FHE.eint<2>) -> !FHE.eint<2>
"FHE.sub_int_eint"(%i, %a) : (i3, !FHE.eint<2>) -> !FHE.eint<3>
"FHE.sub_int_eint"(%i, %a) : (i3, !FHE.eint<2>) -> !FHE.esint<2>

Traits: AlwaysSpeculatableImplTrait

Interfaces: Binary, BinaryIntEint, ConditionallySpeculatable, NoMemoryEffect (MemoryEffectOpInterface)

Effects: MemoryEffects::Effect{}

Operands:

Results:

FHE.to_bool (::mlir::concretelang::FHE::ToBoolOp)

Cast an unsigned integer to a boolean

The input must be of width one or two. Two being the current representation of an encrypted boolean, leaving one bit for the carry.

Examples:

// ok
"FHE.to_bool"(%x) : (!FHE.eint<1>) -> !FHE.ebool
"FHE.to_bool"(%x) : (!FHE.eint<2>) -> !FHE.ebool

// error
"FHE.to_bool"(%x) : (!FHE.eint<3>) -> !FHE.ebool

Traits: AlwaysSpeculatableImplTrait

Interfaces: ConditionallySpeculatable, NoMemoryEffect (MemoryEffectOpInterface), UnaryEint

Effects: MemoryEffects::Effect{}

Operands:

Results:

FHE.to_signed (::mlir::concretelang::FHE::ToSignedOp)

Cast an unsigned integer to a signed one

The result must have the same width as the input.

The behavior is undefined on overflow/underflow.

Examples:

// ok
"FHE.to_signed"(%x) : (!FHE.eint<2>) -> !FHE.esint<2>

// error
"FHE.to_signed"(%x) : (!FHE.eint<2>) -> !FHE.esint<3>

Traits: AlwaysSpeculatableImplTrait

Interfaces: ConditionallySpeculatable, NoMemoryEffect (MemoryEffectOpInterface), UnaryEint

Effects: MemoryEffects::Effect{}

Operands:

Results:

FHE.to_unsigned (::mlir::concretelang::FHE::ToUnsignedOp)

Cast a signed integer to an unsigned one

The result must have the same width as the input.

The behavior is undefined on overflow/underflow.

Examples:

// ok
"FHE.to_unsigned"(%x) : (!FHE.esint<2>) -> !FHE.eint<2>

// error
"FHE.to_unsigned"(%x) : (!FHE.esint<2>) -> !FHE.eint<3>

Traits: AlwaysSpeculatableImplTrait

Interfaces: ConditionallySpeculatable, NoMemoryEffect (MemoryEffectOpInterface), UnaryEint

Effects: MemoryEffects::Effect{}

Operands:

Results:

FHE.zero (::mlir::concretelang::FHE::ZeroEintOp)

Returns a trivial encrypted integer of 0

Example:

"FHE.zero"() : () -> !FHE.eint<2>
"FHE.zero"() : () -> !FHE.esint<2>

Traits: AlwaysSpeculatableImplTrait

Interfaces: ConditionallySpeculatable, ConstantNoise, NoMemoryEffect (MemoryEffectOpInterface)

Effects: MemoryEffects::Effect{}

Results:

FHE.zero_tensor (::mlir::concretelang::FHE::ZeroTensorOp)

Creates a new tensor with all elements initialized to an encrypted zero.

Creates a new tensor with the shape specified in the result type and initializes its elements with an encrypted zero.

Example:

%tensor = "FHE.zero_tensor"() : () -> tensor<5x!FHE.eint<4>>
%tensor = "FHE.zero_tensor"() : () -> tensor<5x!FHE.esint<4>>

Traits: AlwaysSpeculatableImplTrait

Interfaces: ConditionallySpeculatable, ConstantNoise, NoMemoryEffect (MemoryEffectOpInterface)

Effects: MemoryEffects::Effect{}

Results:

Type definition

EncryptedBooleanType

An encrypted boolean

Syntax: !FHE.ebool

An encrypted boolean.

EncryptedSignedIntegerType

An encrypted signed integer

An encrypted signed integer with width bits to performs FHE Operations.

Examples:

!FHE.esint<7>
!FHE.esint<6>

Parameters:

EncryptedUnsignedIntegerType

An encrypted unsigned integer

An encrypted unsigned integer with width bits to performs FHE Operations.

Examples:

!FHE.eint<7>
!FHE.eint<6>

Parameters:

Runtime dialect A dialect for representation the abstraction needed for the runtime.

Operation definition

RT.await_future (::mlir::concretelang::RT::AwaitFutureOp)

Wait for a future and access its data.

The results of a dataflow task are always futures which could be further used as inputs to subsequent tasks. When the result of a task is needed in the outer execution context, the result future needs to be synchronized and its data accessed using RT.await_future.

Operands:

Results:

RT.build_return_ptr_placeholder (::mlir::concretelang::RT::BuildReturnPtrPlaceholderOp)

Results:

RT.clone_future (::mlir::concretelang::RT::CloneFutureOp)

Interfaces: AllocationOpInterface, MemoryEffectOpInterface

Operands:

Results:

RT.create_async_task (::mlir::concretelang::RT::CreateAsyncTaskOp)

Create a dataflow task.

Attributes:

Operands:

RT.dataflow_task (::mlir::concretelang::RT::DataflowTaskOp)

Dataflow task operation

RT.dataflow_task allows to specify a task that will be concurrently executed when their operands are ready. Operands are either the results of computation in other RT.dataflow_task (dataflow dependences) or obtained from the execution context (immediate operands). Operands are synchronized using futures and, in the case of immediate operands, copied when the task is created. Caution is required when the operand is a pointer as no deep copy will occur.

Example:

func @test(%0 : i64): (i64, i64) {
    // Execute right now as %0 is ready.
    %1, %2 = "RT.dataflow_task"(%0) ({
        %a = addi %0, %0 : i64
        %b = muli %0, %0 : i64
        "RT.dataflow_yield"(%a, %b) : (i64, i64) -> i64
    }) : (i64, i64) -> (i64, i64)
    // Concurrently execute both tasks below when the task above is completed.
    %3 = "RT.dataflow_task"(%1) ({
        %c = constant 1 : %i64
        %a = addi %1, %c : i64
        "RT.dataflow_yield"(%a) : (i64, i64) -> i64
    }) : (i64, i64) -> (i64, i64)
    %4 = "RT.dataflow_task"(%2) ({
        %c = constant 2 : %i64
        %a = addi %2, %c : i64
        "RT.dataflow_yield"(%a) : (i64, i64) -> i64
    }) : (i64, i64) -> (i64, i64)
    return %3, %4 : (i64, i64)
}

Traits: AutomaticAllocationScope, SingleBlockImplicitTerminator

Interfaces: AllocationOpInterface, MemoryEffectOpInterface, RegionBranchOpInterface

Operands:

Results:

RT.dataflow_yield (::mlir::concretelang::RT::DataflowYieldOp)

Dataflow yield operation

RT.dataflow_yield is a special terminator operation for blocks inside the region in RT.dataflow_task. It allows to specify the return values of a RT.dataflow_task.

Example:

%0 = constant 1 : i64
%1 = constant 2 : i64
"RT.dataflow_yield" %0, %1 : i64, i64

Traits: ReturnLike, Terminator

Operands:

RT.deallocate_future_data (::mlir::concretelang::RT::DeallocateFutureDataOp)

Operands:

RT.deallocate_future (::mlir::concretelang::RT::DeallocateFutureOp)

Operands:

RT.deref_return_ptr_placeholder (::mlir::concretelang::RT::DerefReturnPtrPlaceholderOp)

Operands:

Results:

RT.deref_work_function_argument_ptr_placeholder (::mlir::concretelang::RT::DerefWorkFunctionArgumentPtrPlaceholderOp)

Operands:

Results:

RT.make_ready_future (::mlir::concretelang::RT::MakeReadyFutureOp)

Build a ready future.

Data passed to dataflow tasks must be encapsulated in futures, including immediate operands. These must be converted into futures using RT.make_ready_future.

Interfaces: AllocationOpInterface, MemoryEffectOpInterface

Operands:

Results:

RT.register_task_work_function (::mlir::concretelang::RT::RegisterTaskWorkFunctionOp)

Register the task work-function with the runtime system.

Operands:

RT.work_function_return (::mlir::concretelang::RT::WorkFunctionReturnOp)

Operands:

Type definition

FutureType

Future with a parameterized element type

The value of a !RT.future type represents the result of an asynchronous operation.

Examples:

!RT.future<i64>

Parameters:

PointerType

Pointer to a parameterized element type

Parameters:

Dialect for the construction of static data flow graphs A dialect for the construction of static data flow graphs. The data flow graph is composed of a set of processes, connected through data streams. Special streams allow for data to be injected into and to be retrieved from the data flow graph.

Operation definition

SDFG.get (::mlir::concretelang::SDFG::Get)

Retrieves a data element from a stream

Retrieves a single data element from the specified stream (i.e., an instance of the element type of the stream).

Example:

"SDFG.get" (%stream) : (!SDFG.stream<1024xi64>) -> (tensor<1024xi64>)

Operands:

Results:

SDFG.init (::mlir::concretelang::SDFG::Init)

Initializes the streaming framework

Initializes the streaming framework. This operation must be performed before control reaches any other operation from the dialect.

Example:

"SDFG.init" : () -> !SDFG.dfg

Results:

SDFG.make_process (::mlir::concretelang::SDFG::MakeProcess)

Creates a new SDFG process

Creates a new SDFG process and connects it to the input and output streams.

Example:

%in0 = "SDFG.make_stream" { type = #SDFG.stream_kind<host_to_device> }(%dfg) : (!SDFG.dfg) -> !SDFG.stream<tensor<1024xi64>>
%in1 = "SDFG.make_stream" { type = #SDFG.stream_kind<host_to_device> }(%dfg) : (!SDFG.dfg) -> !SDFG.stream<tensor<1024xi64>>
%out = "SDFG.make_stream" { type = #SDFG.stream_kind<device_to_host> }(%dfg) : (!SDFG.dfg) -> !SDFG.stream<tensor<1024xi64>>
"SDFG.make_process" { type = #SDFG.process_kind<add_eint> }(%dfg, %in0, %in1, %out) :
  (!SDFG.dfg, !SDFG.stream<tensor<1024xi64>>, !SDFG.stream<tensor<1024xi64>>, !SDFG.stream<tensor<1024xi64>>) -> ()

Attributes:

Operands:

SDFG.make_stream (::mlir::concretelang::SDFG::MakeStream)

Returns a new SDFG stream

Returns a new SDFG stream, transporting data either between processes on the device, from the host to the device or from the device to the host. All streams are typed, allowing data to be read / written through SDFG.get and SDFG.put only using the stream's type.

Example:

"SDFG.make_stream" { name = "stream", type = #SDFG.stream_kind<host_to_device> }(%dfg)
  : (!SDFG.dfg) -> !SDFG.stream<tensor<1024xi64>>

Attributes:

Operands:

Results:

SDFG.put (::mlir::concretelang::SDFG::Put)

Writes a data element to a stream

Writes the input operand to the specified stream. The operand's type must meet the element type of the stream.

Example:

"SDFG.put" (%stream, %data) : (!SDFG.stream<1024xi64>, tensor<1024xi64>) -> ()

Operands:

SDFG.shutdown (::mlir::concretelang::SDFG::Shutdown)

Shuts down the streaming framework

Shuts down the streaming framework. This operation must be performed after any other operation from the dialect.

Example:

"SDFG.shutdown" (%dfg) : !SDFG.dfg

Operands:

SDFG.start (::mlir::concretelang::SDFG::Start)

Finalizes the creation of an SDFG and starts execution of its processes

Finalizes the creation of an SDFG and starts execution of its processes. Any creation of streams and processes must take place before control reaches this operation.

Example:

"SDFG.start"(%dfg) : !SDFG.dfg

Operands:

Attribute definition

ProcessKindAttr

Process kind

Syntax:

#SDFG.process_kind<
  ::mlir::concretelang::SDFG::ProcessKind   # value
>

Parameters:

StreamKindAttr

Stream kind

Syntax:

#SDFG.stream_kind<
  ::mlir::concretelang::SDFG::StreamKind   # value
>

Parameters:

Type definition

DFGType

An SDFG data flow graph

Syntax: !SDFG.dfg

A handle to an SDFG data flow graph

StreamType

An SDFG data stream

An SDFG stream to connect SDFG processes.

Parameters:

High Level Fully Homomorphic Encryption dialect A dialect for representation of high level operation on fully homomorphic ciphertext.

Operation definition

TFHE.batched_add_glwe_cst_int (::mlir::concretelang::TFHE::ABatchedAddGLWECstIntOp)

Batched version of AddGLWEIntOp

Traits: AlwaysSpeculatableImplTrait

Interfaces: ConditionallySpeculatable, NoMemoryEffect (MemoryEffectOpInterface)

Effects: MemoryEffects::Effect{}

Operands:

Results:

TFHE.batched_add_glwe_int_cst (::mlir::concretelang::TFHE::ABatchedAddGLWEIntCstOp)

Batched version of AddGLWEIntOp

Traits: AlwaysSpeculatableImplTrait

Interfaces: ConditionallySpeculatable, NoMemoryEffect (MemoryEffectOpInterface)

Effects: MemoryEffects::Effect{}

Operands:

Results:

TFHE.batched_add_glwe_int (::mlir::concretelang::TFHE::ABatchedAddGLWEIntOp)

Batched version of AddGLWEIntOp

Traits: AlwaysSpeculatableImplTrait

Interfaces: ConditionallySpeculatable, NoMemoryEffect (MemoryEffectOpInterface)

Effects: MemoryEffects::Effect{}

Operands:

Results:

TFHE.batched_add_glwe (::mlir::concretelang::TFHE::ABatchedAddGLWEOp)

Batched version of AddGLWEOp

Traits: AlwaysSpeculatableImplTrait

Interfaces: ConditionallySpeculatable, NoMemoryEffect (MemoryEffectOpInterface)

Effects: MemoryEffects::Effect{}

Operands:

Results:

TFHE.add_glwe_int (::mlir::concretelang::TFHE::AddGLWEIntOp)

Returns the sum of a clear integer and an lwe ciphertext

Traits: AlwaysSpeculatableImplTrait

Interfaces: BatchableOpInterface, ConditionallySpeculatable, NoMemoryEffect (MemoryEffectOpInterface)

Effects: MemoryEffects::Effect{}

Operands:

Results:

TFHE.add_glwe (::mlir::concretelang::TFHE::AddGLWEOp)

Returns the sum of two lwe ciphertexts

Traits: AlwaysSpeculatableImplTrait

Interfaces: BatchableOpInterface, ConditionallySpeculatable, NoMemoryEffect (MemoryEffectOpInterface)

Effects: MemoryEffects::Effect{}

Operands:

Results:

TFHE.batched_bootstrap_glwe (::mlir::concretelang::TFHE::BatchedBootstrapGLWEOp)

Batched version of KeySwitchGLWEOp

Traits: AlwaysSpeculatableImplTrait

Interfaces: ConditionallySpeculatable, NoMemoryEffect (MemoryEffectOpInterface)

Effects: MemoryEffects::Effect{}

Attributes:

Operands:

Results:

TFHE.batched_keyswitch_glwe (::mlir::concretelang::TFHE::BatchedKeySwitchGLWEOp)

Batched version of KeySwitchGLWEOp

Traits: AlwaysSpeculatableImplTrait

Interfaces: ConditionallySpeculatable, NoMemoryEffect (MemoryEffectOpInterface)

Effects: MemoryEffects::Effect{}

Attributes:

Operands:

Results:

TFHE.batched_mapped_bootstrap_glwe (::mlir::concretelang::TFHE::BatchedMappedBootstrapGLWEOp)

Batched version of KeySwitchGLWEOp which also batches the lookup table

Traits: AlwaysSpeculatableImplTrait

Interfaces: ConditionallySpeculatable, NoMemoryEffect (MemoryEffectOpInterface)

Effects: MemoryEffects::Effect{}

Attributes:

Operands:

Results:

TFHE.batched_mul_glwe_cst_int (::mlir::concretelang::TFHE::BatchedMulGLWECstIntOp)

Batched version of MulGLWEIntOp

Traits: AlwaysSpeculatableImplTrait

Interfaces: ConditionallySpeculatable, NoMemoryEffect (MemoryEffectOpInterface)

Effects: MemoryEffects::Effect{}

Operands:

Results:

TFHE.batched_mul_glwe_int_cst (::mlir::concretelang::TFHE::BatchedMulGLWEIntCstOp)

Batched version of MulGLWEIntOp

Traits: AlwaysSpeculatableImplTrait

Interfaces: ConditionallySpeculatable, NoMemoryEffect (MemoryEffectOpInterface)

Effects: MemoryEffects::Effect{}

Operands:

Results:

TFHE.batched_mul_glwe_int (::mlir::concretelang::TFHE::BatchedMulGLWEIntOp)

Batched version of MulGLWEIntOp

Traits: AlwaysSpeculatableImplTrait

Interfaces: ConditionallySpeculatable, NoMemoryEffect (MemoryEffectOpInterface)

Effects: MemoryEffects::Effect{}

Operands:

Results:

TFHE.batched_neg_glwe (::mlir::concretelang::TFHE::BatchedNegGLWEOp)

Batched version of NegGLWEOp

Traits: AlwaysSpeculatableImplTrait

Interfaces: ConditionallySpeculatable, NoMemoryEffect (MemoryEffectOpInterface)

Effects: MemoryEffects::Effect{}

Operands:

Results:

TFHE.bootstrap_glwe (::mlir::concretelang::TFHE::BootstrapGLWEOp)

Programmable bootstraping of a GLWE ciphertext with a lookup table

Traits: AlwaysSpeculatableImplTrait

Interfaces: BatchableOpInterface, ConditionallySpeculatable, NoMemoryEffect (MemoryEffectOpInterface)

Effects: MemoryEffects::Effect{}

Attributes:

Operands:

Results:

TFHE.encode_expand_lut_for_bootstrap (::mlir::concretelang::TFHE::EncodeExpandLutForBootstrapOp)

Encode and expand a lookup table so that it can be used for a bootstrap.

Traits: AlwaysSpeculatableImplTrait

Interfaces: ConditionallySpeculatable, NoMemoryEffect (MemoryEffectOpInterface)

Effects: MemoryEffects::Effect{}

Attributes:

Operands:

Results:

TFHE.encode_lut_for_crt_woppbs (::mlir::concretelang::TFHE::EncodeLutForCrtWopPBSOp)

Encode and expand a lookup table so that it can be used for a wop pbs.

Traits: AlwaysSpeculatableImplTrait

Interfaces: ConditionallySpeculatable, NoMemoryEffect (MemoryEffectOpInterface)

Effects: MemoryEffects::Effect{}

Attributes:

Operands:

Results:

TFHE.encode_plaintext_with_crt (::mlir::concretelang::TFHE::EncodePlaintextWithCrtOp)

Encodes a plaintext by decomposing it on a crt basis.

Traits: AlwaysSpeculatableImplTrait

Interfaces: ConditionallySpeculatable, NoMemoryEffect (MemoryEffectOpInterface)

Effects: MemoryEffects::Effect{}

Attributes:

Operands:

Results:

TFHE.keyswitch_glwe (::mlir::concretelang::TFHE::KeySwitchGLWEOp)

Change the encryption parameters of a glwe ciphertext by applying a keyswitch

Traits: AlwaysSpeculatableImplTrait

Interfaces: BatchableOpInterface, ConditionallySpeculatable, NoMemoryEffect (MemoryEffectOpInterface)

Effects: MemoryEffects::Effect{}

Attributes:

Operands:

Results:

TFHE.mul_glwe_int (::mlir::concretelang::TFHE::MulGLWEIntOp)

Returns the product of a clear integer and an lwe ciphertext

Traits: AlwaysSpeculatableImplTrait

Interfaces: BatchableOpInterface, ConditionallySpeculatable, NoMemoryEffect (MemoryEffectOpInterface)

Effects: MemoryEffects::Effect{}

Operands:

Results:

TFHE.neg_glwe (::mlir::concretelang::TFHE::NegGLWEOp)

Negates a glwe ciphertext

Traits: AlwaysSpeculatableImplTrait

Interfaces: BatchableOpInterface, ConditionallySpeculatable, NoMemoryEffect (MemoryEffectOpInterface)

Effects: MemoryEffects::Effect{}

Operands:

Results:

TFHE.sub_int_glwe (::mlir::concretelang::TFHE::SubGLWEIntOp)

Substracts an integer and a GLWE ciphertext

Traits: AlwaysSpeculatableImplTrait

Interfaces: ConditionallySpeculatable, NoMemoryEffect (MemoryEffectOpInterface)

Effects: MemoryEffects::Effect{}

Operands:

Results:

TFHE.wop_pbs_glwe (::mlir::concretelang::TFHE::WopPBSGLWEOp)

Traits: AlwaysSpeculatableImplTrait

Interfaces: ConditionallySpeculatable, NoMemoryEffect (MemoryEffectOpInterface)

Effects: MemoryEffects::Effect{}

Attributes:

Operands:

Results:

TFHE.zero (::mlir::concretelang::TFHE::ZeroGLWEOp)

Returns a trivial encryption of 0

Traits: AlwaysSpeculatableImplTrait

Interfaces: ConditionallySpeculatable, NoMemoryEffect (MemoryEffectOpInterface)

Effects: MemoryEffects::Effect{}

Results:

TFHE.zero_tensor (::mlir::concretelang::TFHE::ZeroTensorGLWEOp)

Returns a tensor containing trivial encryptions of 0

Traits: AlwaysSpeculatableImplTrait

Interfaces: ConditionallySpeculatable, NoMemoryEffect (MemoryEffectOpInterface)

Effects: MemoryEffects::Effect{}

Results:

Attribute definition

GLWEBootstrapKeyAttr

An attribute representing bootstrap key.

Syntax:

Parameters:

GLWEKeyswitchKeyAttr

An attribute representing keyswitch key.

Syntax:

Parameters:

GLWEPackingKeyswitchKeyAttr

An attribute representing Wop Pbs key.

Syntax:

Parameters:

Type definition

GLWECipherTextType

A GLWE ciphertext

An GLWE cipher text

Parameters: