[Cryptography] Leo Marks' 1998 talk about WW2 SOE code-making and breaking

[John Gilmore]

Leo Marks was an excellent cryptographer recruited at age 21 into the
British SOE (Special Operations Executive) which ran a large network of
spies and saboteurs in every country in Europe.  He eventually became
Chief of Codes and made it his goal to increase the average lifetime of
an agent sent into the field (from its dismal start of a few weeks).
Despite massive bureaucratic inertia and infighting, he not only
independently invented one-time pads (using letters rather than
numbers), but also came up with many small and large coding tweaks that
made the agents' jobs easier and the German spy-catchers' jobs much harder.

As SOE was being disbanded after the war, he wrote a long history of
everything that had happened in codes and ciphers.  Foolishly, but
legally, he didn't keep a copy.  SOE's historians have lost all copies.
In the early 1980s Leo wrote a book, _Between Silk and Cyanide_, with all
the history that he could remember or dig back up.  It was finally
published in 1998 after the British government censored it for more than
a decade.  He died of cancer in 2001.

But in 1998, he gave a 23-minute talk on "Codes and Ciphers" at the
Imperial War Museum in London.  That talk was recorded, and it's now
online:

  https://www.iwm.org.uk/collections/item/object/80017694

It's a lot like reading his book in 23 minutes!  There are lots more
details in the book, and lots of the irreverent black humor that kept
him going in the darkest times.  So after hearing his voice, I still
recommend reading the book.

So much of code-making and code-breaking (e.g. in academia or business)
is completely ill-informed by actual operational experience.  Leo never
had that luxury.  He has tried to teach us almost everything that he
learned.  Worth listening to!

	John

PS: This reminds me -- at the Santa Barbara Crypto '95 conference, after
leaving NSA, Bob Morris Sr gave a talk on "Non-cryptographic Ways of
Losing Information".  His Rule #1 for cryptanalysis: "check for
plaintext", because you'll find it remarkably often in real life.  Jim
Gillogly posted notes from the talk to sci.crypt, which are findable
from Morris's Wikipedia page:

  https://en.wikipedia.org/wiki/Robert_Morris_(cryptographer)

Do there exist any recordings of *that* talk?