v0 Parameters
The v0-parameters tool provides crypto-parameters that guarantee security, correctness and fast
computation without prior knowledge of the crypto-parameter optimization.
It can also be used to explore the crypto-parameter space w.r.t. the 2-norm of the dot product, the precision or even the failure probability.
For now, we only support two kind of atomic patterns but more will be added in the near future.
Supported Atomic Patterns
Default Atomic Pattern
The default atomic pattern is composed of a dot product between ciphertexts and integer weights, an LWE-to-LWE keyswitch and a PBS i.e.
This atomic pattern allows to compute over encrypted data a dot product and a lookup-table evaluation for precision between 1 and 8 (with the default failure probability) and 2-norm between 2^0 and 2^25. The 2-norm is defined as the 2-norm v of the weights of the Dot Product. It is used as a metric to quantify the impact of the leveled operations between two PBS on the noise (here a DotProduct). Note that an atomic pattern can be described by its precision and 2-norm but only in the case that every inputs are independents from one another (regarding the noise).
New Atomic Pattern
Another atomic pattern is available leveraging the new WoP-PBS (Without-Padding Programmable Bootstrapping) described in this paper. It is composed of a dot product between ciphertexts and integer weights and a WoP-PBS.
Using this new AP, we can find parameters for precision up to 16 bits 🥳 using the optional flag --wop-pbs like that
cargo run --release -- --wop-pbs
Usage
The v0-parameters tool can take several parameters as arguments. The summary of all available
arguments is accessible by running in the v0-parameters/ folder
cargo run --release -- --help
As an alternative you can use the optimizer script in the root directory:
./optimizer --help
By default, the optimization is done on the default AP (DotProduct -> Ks -> PBS) for every available
precision and for every 2-norm. If not specified, the correctness of the computation is guaranteed
up to a failure probability of 2^-13.9. This can be changed using the --p-error
optional argument.
Try running cargo run --release, you will get the V0 Parameters Table that was previously used
in concrete-compiler.
Advanced Usage
Playing with search spaces
It is possible to choose the search space for each cryptographic parameters. For example, here we constrain the glwe dimension to be equal to 1:
cargo run --release -- --max-glwe-dim 1
Generating reference files
Some of our tests are comparing parameters found by previous version of concrete-optimizer against
the parameters found by the current state of concrete-optimizer.
To generate those references, you must be in v0-parameters directory. For the default AP you can do:
cargo run --release --bin v0-parameters-by-level
and for the new WoP-PBS AP
cargo run --release --bin v0-parameters-by-level -- --wop-pbs
The reference files will be written in the ref/ folder.