This public key can be used with release 12.9.1 (driver v. 3.27.1) and later.

Import the public key into the RPM database

$ sudo rpm --import RPM_GPG_KEY_NT_RD

List available keys

$ rpm -q gpg-pubkey --qf '%{name}-%{version}-%{release} --> %{summary}\n'
gpg-pubkey-f4a80eb5-53a7ff4b --> gpg(CentOS-7 Key (CentOS 7 Official Signing Key) <security@centos.org>)
gpg-pubkey-352c64e5-52ae6884 --> gpg(Fedora EPEL (7) <epel@fedoraproject.org>)
gpg-pubkey-52bdea88-62bec77f --> gpg(Napatech A/S <sw@napatech.com>)

Check the signature of an RPM package signed by Napatech

$ rpm --checksig nt-driver-3gd-3.26.1.168-28830046.src.rpm
nt-driver-3gd-3.26.1.168-28830046.src.rpm: rsa sha1 (md5) pgp md5 OK

The presence of pgp shows the package is signed with a known key.