Requirements
Install the open source software 7Zip, which has a nice interface for this. After it’s installed, log out an back in.
Windows Users
Create a zip file
In Explorer, select multiple items. Right click and in the context menu go to
7-Zip → Add to “foldername.zip”
Create a Checksum
Think of a checksum as a certificate of authenticity for your file. It ensures that the file has not been altered or corrupted during transfer.
Next, right click the new zip file and go to
7-Zip → CRC SHA → SHA-256 - foldername.zip.sha256
Go back to the Homepage to finish the steps
Mac Users
I don’t have a Mac, but everything should work the same. I’ll be borrowing a Mac soon to test this out.