If you don't have Go installed, download it from here or install it from your package manager. Next:

go install github.com/Picocrypt/CLI/picocrypt@latest

You should now be able to run picocrypt in your terminal. If not, run export PATH=$PATH:$(go env GOPATH)/bin and try again.

Alternatively, you can use the prebuilt binaries in Releases.

C:\Users\Evan>picocrypt
Usage: picocrypt <item1> [<item2> ...]
Items: can be files, folders, or globs
Flags:
  -f    (decryption) attempt to fix corruption
  -k    (decryption) keep output even if corrupted
  -p    (encryption) use paranoid mode
  -r    (encryption) encode with Reed-Solomon

To encrypt a single file:

picocrypt secret.pdf

To encrypt all files in the current working directory:

picocrypt *

To encrypt all PNGs and JPGs with paranoid mode and Reed-Solomon:

picocrypt -p -r *.png *.jpg

To decrypt a volume:

picocrypt volume.pcv