If Russia and China had actually cracked the encryption around Snowden's files, would the Brits be publicising it to the world? I don't think so. The Brits would
not want to let the Russians/Chinese to know they (the Brits) know.
And once Snowden's exploits were known to the Brits (several years ago), why would the Brits not have taken precautionary measures to prevent problems like
this from occuring, unless the Brits are just exceedingly stupid (which I doubt).
How can we verify the truth, or lack thereof, of this report? I doubt we can, short of having our own agents inside MI6.
Why would the Russians/Chinese give the first hint of a sniff of a clue that they have decrypted these files? I don't think they would, as it would be beyond stupid
to do so. Let the Brits keep their agents in place and feed them bad info.
This whole thing smells quite fishy to me.