Comment 11 for bug 1854148

The pool for the ppa is at http://ppa.launchpad.net/brian-murray/ppa/ubuntu/

you can use dget to fetch the source packages; and dpkg-source -x to extract them,

i.e.

dget http://ppa.launchpad.net/brian-murray/ppa/ubuntu/pool/main/o/opencryptoki/opencryptoki_3.9.0+dfsg-0ubuntu1.3~ppa2.dsc

dpkg-source -x opencryptoki_3.9.0+dfsg-0ubuntu1.3~ppa2.dsc

Also note, when testing a PPA, you are not expected to install .deb files by hand, but instead enable PPA and simply upgrade all the packages from it. I.e.

sudo add-apt-repository ppa:brian-murray/ppa
sudo apt update
sudo apt full-upgrade

These intructions are listed on "add this ppa to your system" on the https://launchpad.net/~brian-murray/+archive/ubuntu/ppa

That's more secure than downloading debs, as GPG signatures for the archive are verified & checksums of the debs are validated.