More Detail on Cairncross at Bletchley Park

Last week saw a major release to The National Archives of MI5 files, mainly concerning ‘The Cambridge Five’ or at least the three of them, Philby, Blunt and Cairncross, whom MI5 had the opportunity to investigate (Burgess and Maclean having skipped the jurisdiction).

I’ve obviously not been able to go through this new material in any detail, but I have looked at the parts of the Cairncross files which shed light on his time at Bletchley Park.

I covered some of this three years ago in Sigint Historian: Personnel Security at Bletchley Park - Part Two

There is some interesting new (to me) detail. Cairncross had been encouraged by his controller to join GC&S or SIS. When he first identified to MI5 the battle in which the Ultra material he had passed to his controller had given the Red Army a decisive advantage over the Germans he claimed it was the Battle of Kharkov (Kharkiv, of course, today), not Kursk. Interviewed in 1967, Peter Wright asked him whether he could remember anybody at Bletchley who might have been pro-Russian: his answer was that everybody at BP was pro-Russian because of the events of the war, but he named three people Hugo Gatti, Philip Pounsey and Douglas Parmier, but these are likely simply to be three names plucked out of the air. (None appear on the Bletchley Park Roll of Honour.)

More insidiously, he said that his Soviet controller had once asked him why a former FO colleague, Roddy Greiffenhagen, had transferred to GC&CS, and whether this move would hit Greiffenhagen financially. After some investigation, MI5 discovered that Greiffenhagen was eased out of the FO ‘because of his total inability to do the work required’, and concluded that Cairncross was likely to have passed biographical details of other FO colleagues to the Soviets as well. He admitted to having passed a couple of pen pictures of GC&CS colleagues to his controller, but couldn’t remember who they were. This part of the release leaves a question mark over Greiffenhagen’s reputation: it’s a bit unfair, as there was no doubt an investigation subsequently: one, potentially, for a future release.

Cairncross said that his controller was annoyed when he engineered a transfer for himself from BP to SIS Section V at Ryder St to work on counter espionage (a section to which GC&CS deployed several members of staff as it began to resume its work on Soviet targets), the annoyance, he claimed, being because of the quality of the material he was passing from Hut 3. I wonder whether the presence there already of Kim Philby might have been a better reason for the controller’s annoyance.

There is a curious tale of Cairncross at Ryder St pestering somebody (whose name is redacted) at Berkeley St (where GC&CS diplomatic traffic was worked) to get information about a breakthrough made by Berkeley St. The unnamed person said that he had probably been indiscreet at the time, but reflecting on matters in 1967, thought that as Philby was handling this material, his indiscretions were probably not that relevant.

There is an amusing 1955 account by Henry Dryden (a Second World War Siginter who stayed on after the war). In the spring of 1949 Cairncross phoned Dryden at GCHQ, then at Eastcote, inviting him to lunch, and over the soup course asked whether GCHQ was a successful with Soviet encryption as it had been with German. Dryden ‘mumbled some sort of non-committal reply, bringing in the phrase “one-time pad” and tried to give the impression that one could not do anything to make progress’. This story, at least, is already in the public domain, having been told by Dryden in 1993, in a postscript to his contribution to Hinsley and Stripp’s Codebreakers.

There may well be more details in these files, and I’m sure there will certainly be in other files in the release, but three things stand out to me. The first is something I have mentioned before: how little the MI5 investigators knew of (never mind understood) how Sigint worked and their consequently appearing to deal with it as not as key an issue as were some others. The second, is that my judgement of three years ago, that of course it was likely there were other Soviet sympathisers at Bletchley, but that they were unlikely to have been able to pass on many great secrets, hasn’t changed, not least because of the third: that only if somebody had access to Bletchley’s serialised reported intelligence would it be possible to pass intelligible information to a hostile intelligence service.