Where to download ppk encryption?

PPK (PuTTY Private Key) files are typically generated using the PuTTYgen tool, which is part of the PuTTY suite. You can download the PuTTY software, including PuTTYgen, from the official PuTTY website at www.putty.org. Follow the installation instructions, and use PuTTYgen to create or convert keys into the PPK format.