For openSUSE Tumbleweed run the following as root:
zypper addrepo https://download.opensuse.org/repositories/home:Simmphonie:yubico/openSUSE_Tumbleweed/home:Simmphonie:yubico.repo
zypper refresh
zypper install python-cryptography
For 16.0 run the following as root:
zypper addrepo https://download.opensuse.org/repositories/home:Simmphonie:yubico/16.0/home:Simmphonie:yubico.repo
zypper refresh
zypper install python-cryptography
For 15.6 run the following as root:
zypper addrepo https://download.opensuse.org/repositories/home:Simmphonie:yubico/15.6/home:Simmphonie:yubico.repo
zypper refresh
zypper install python-cryptography