Mgmt

‘mgmt’ Dialect

The mgmt dialect contains scheme-agnostic ciphertext management ops (like relinearize and mod reduce), to enable initial high-level compiler passes to perform a first pass at parameter selection, while lower-level passes may refine them with scheme-specific information.

Mgmt attributes

MgmtAttr

Container attribute for all mgmt parameter

Syntax:

#mgmt.mgmt<
  int,   # level
  int   # dimension
>

This attribute is used to store all mgmt parameters.

The attribute is a struct with the following fields:

• level : the level of the ciphertext, from L to 0
• dimension : the dimension of the ciphertext, defaults to 2

Internally, this attribute is used by secret-to- for determining the level and dimension of the ciphertext.

It should be populated by –secret-with-mgmt- before going through the secret-to- pass.

Example:

#mgmt = #mgmt.mgmt<level = 1> // dimension defaults to 2
#mgmt1 = #mgmt.mgmt<level = 1, dimension = 3>
%0 = secret.generic ins(%arg0, %arg1 : !secret.secret<i16>) attrs = {mgmt.mgmt = #mgmt} {
   ...
} -> !secret.secret<i16>

Parameters:

Mgmt ops

mgmt.bootstrap (heir::mgmt::BootstrapOp)

Bootstrap the input ciphertext to refresh its noise budget

Syntax:

operation ::= `mgmt.bootstrap` operands attr-dict `:` type($output)

This is a scheme-agnostic operation that implies bootstrapping of the input ciphertext to refresh its noise budget.

Bootstrapping is a technique used in homomorphic encryption to reduce the noise in a ciphertext, allowing further operations to be performed on it without decryption.

When further lowered, it could be lowered to bgv.bootstrap or ckks.bootstrap depending on the scheme.

For the current backend, only ckks.bootstrap is supported. Further backend may include bgv.bootstrap.

Traits: AlwaysSpeculatableImplTrait, Elementwise, SameOperandsAndResultType, Scalarizable, Tensorizable, Vectorizable

Interfaces: ConditionallySpeculatable, InferTypeOpInterface, NoMemoryEffect (MemoryEffectOpInterface)

Effects: MemoryEffects::Effect{}

Operands:

Results:

mgmt.modreduce (heir::mgmt::ModReduceOp)

Modulus switch the input ciphertext down by one limb (RNS assumed)

Syntax:

operation ::= `mgmt.modreduce` operands attr-dict `:` type($output)

This is scheme-agonistic operation that implies modulus switching/rescaling by one limb.

Input ciphertext is assumed to be in RNS form when further lowered.

When further lowered, it could be lowered to bgv.modulus_switch or ckks.rescale depending on the scheme.

Traits: AlwaysSpeculatableImplTrait, Elementwise, SameOperandsAndResultType, Scalarizable, Tensorizable, Vectorizable

Interfaces: ConditionallySpeculatable, InferTypeOpInterface, NoMemoryEffect (MemoryEffectOpInterface)

Effects: MemoryEffects::Effect{}

Operands:

Results:

mgmt.relinearize (heir::mgmt::RelinearizeOp)

Relinearize the input ciphertext to be linear

Syntax:

operation ::= `mgmt.relinearize` operands attr-dict `:` type($output)

This is scheme-agonistic operation that implies relinearization of the input ciphertext to be linear (i.e. returns to dimension 2).

This is used solely by multiplication. For rotation, currently HEIR assumes relinearization is done internally and does not have a separate scheme-specific operation for it.

This accepts a ciphertext with dimension > 2 and returns a ciphertext with dimension 2. Note that the semantic includes the relinearization of higher dimension input like input with dimension 4 or higher, which when materialized should require multiple relinearization keys.

When further lowered, it could be lowered to bgv.relinearize or ckks.relinearize depending on the scheme.

Traits: AlwaysSpeculatableImplTrait, Elementwise, SameOperandsAndResultType, Scalarizable, Tensorizable, Vectorizable

Interfaces: ConditionallySpeculatable, InferTypeOpInterface, NoMemoryEffect (MemoryEffectOpInterface)

Effects: MemoryEffects::Effect{}

Operands:

Results: