Back in the days of the spam, I had written an implementation of the note decryption algorithm in CUDA. A RTX 2070 could process 4 Million notes per second. Crunching through the spam took 20 seconds without spam filter, and less than 1 sec with.
However, the users I polled were reluctant to upload their FVK
Also, there is the matter of maintaining a cloud server that has a GPU. They are not cheap.
