Cryptographers tend to be good at cryptography but they can be quite bad at estimating the time it takes a computer to run their schemes.

zkalc helps you calculate how much time cryptographic operations take on a real computer

zkalc was created to instantly answer questions like "How quickly can I run an MSM of size $2^{18}$ and compute $120$ pairings on an AWS C5 machine?" or "Which curve can perform DH in less than $10$ microseconds?".

We hope that zkalc can help shorten the gap between cryptography and practice:

• Cryptographers can use the simple UX to learn how fast their new fancy scheme runs on various machines without wasting computer cycles and CO2;
• Protocol designers can easily tune the parameters of their protocol depending on their requirements

We designed zkalc to be easy to use but also easy to extend. Writing new types of benchmarks, or adding fresh data to the zkalc website is easy. We hope that this way we can motivate you to improve zkalc to better fit your needs. See below for more details.

## zkalc tips

Here are some ways you can squeeze more juice out of zkalc:

• Hover over operations to get more details about them
• Hover over a machine or a library to get more details about the benchmark setup
• Click on the title to reset zkalc
• Click on the total time to get the result in SI units (seconds)
• Type over the dropdown select menu to autocomplete the cryptographic operation
• Type inside the quantity box any arithmetic operation, even common constants like e and pi or functions like log2

## Enriching zkalc

zkalc does not currently support all possible cryptographic operations. For example, we do not currently have benchmarks for FFTs, or batch inversion formulae.

• Find the existing benchmarks in the backend/ directory, and add benchmark code for the new cryptographic operation following the already existing conventions.
• Run all benchmarks on your machine by running make in the backend/ directory.

Last but not least please open a PR with your changes and the json benchmark output files and we will take care of the rest!

In the sections below, we provide more information on how to mod zkalc:

### Benchmarking on another machine

zkalc only supports a few machine types right now. Do you have access to a beefy AWS machine or to some GPU prover? We would love to get in touch!

Simply run all benchmarks on your beefy AWS machine by running make in the backend/ directory. Then open a PR with the json benchmark output files and we will take care of the rest!

If your machine is especially weak (rpi4) or particularly strong (GPU prover) consider modifying the benchmark parameters (e.g. increase/decrease the size of the MSMs) and get in touch with us!

### Testing new curves and libraries

To add benchmarks for a different elliptic curve, write benchmarks for the new curve in the backend/ directory following the already existing conventions.

Note that if your benchmarks do not use the criterion benchmark framework you will need to adapt your benchmark framework to output a JSON file that the zkalc interpolation script understands (it currently understands a small subset of the format of criterion's estimates.json). If you are confused, get in touch and we will help.

Finally, please open a PR with your changes and the json benchmark output files and we will take care of the rest!