Performance of RSA decrypt

[pke]

I am getting 20ms for a 4096bit RSA key decrypting on iOS and 223ms on Android consistently.

Some of the overhead is the React Native bridge, which we can not reduce I think. There are just 2 (relatively small) strings pushed over to the native side.

Could we increase the thread priority for decrypting?

[ghbutton]

I am unsure what are good timings. 223ms on Android sounds terrible, I can look into how to speed this up but am no expert

[pke]

Maybe first step is to increase the task prio. It's currently running on normal prio. Should be highest possible before real-time.

[pke]

Another useful optimisation would be to support blob. Then a request response could be fed to this module without any overhead and directly read from it.

See https://gist.github.com/joshjhargreaves/b0d3f92e05d06d2dd3d6609698621641

[ghbutton]

We can put blob storage as a feature request but increasing the priority on Android seems like a good first step here