Download of KDE LiveCD together with the corresponding checksum from
https://software.opensuse.org/distributions/tumbleweed followed by 
"sha256sum -c
openSUSE-Tumbleweed-KDE-Live-x86_64-Snapshot20191230-Media.iso.sha256" leads to
the error message "sha256sum:
openSUSE-Tumbleweed-KDE-Live.x86_64-2.8.0-Build118.21.iso: file or directory
not found", which is due to the different file names. As a matter of fact, we
have  

> cat openSUSE-Tumbleweed-KDE-Live-x86_64-Snapshot20191230-Media.iso.sha256 
-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA256

86fe34dc48951b2399406d1544d301dfd2733fc634a0677398cb41b762eb74ba 
openSUSE-Tumbleweed-KDE-Live.x86_64-2.8.0-Build118.21.iso
-----BEGIN PGP SIGNATURE-----
...
-----END PGP SIGNATURE-----

While the issue is reported for Tumbleweed, it also applies to other Live
Images/Rescue CD including Leap 15.1/15.2.