Where is the GB DSC S2V5MQ== (Key1) from?

[panzi]

In your trust list is an entry that I cannot find anywhere else. The entry with the binary data converted to Base64 is:

    {
        "kid": "S2V5MQ==",
        "crt": "",
        "iss": {
            "C": "GB"
        },
        "sub": {
            "C": "GB"
        },
        "pub": {
            "x": "LiiJ+fWqqFAJ7gZny/UQV4LgLOdJNpIOFFnLEpSRIBU=",
            "y": "XCrLvnehOOGeslsT/QvUQgJNImw7PRHydmk34M18V1U="
        }
    }

Where do you have that from? It's not in the GB trust list and not in any other that I know of.