Enigma Code Breaker. The Alan Turing story is of a man
who was an English mathematician and widely considered to be the
father of theoretical computer science and artificial
intelligence. Despite these accomplishments, he was never
fully recognised in his home country during his lifetime due
to the prevalence of homophobia, and because much of his work was
covered by the official secrets act. In this video, we look
back now this extraordinary man and his life. Turing's father
Julius Mathison Turing held a position with the Indian civil
service at Chatrapur. Turing's mother, was Ethel
Sarah Turing, daughter of Edward Waller Stoney, and he was chief
engineer of the Madras railways. Julius had worked with the ICS
brought the family to British India, where his grandfather had
been a general in the Bengal army. However, both Julius and
Ethel wanted their children to be brought up in Britain. So
they moved to Maida Vale in London, where Alan Turing was
born on the 23rd of June 1912. He also had an older brother
called John. Turing's father's Civil Service Commission was
still active and during Turing's childhood years, his
parents travelled between Hastings in the UK and India,
leaving their two sons to stay with the retired Army couple.
In 1926, at the age of 13, he went on to Sherborne school, a
boarding independent school in the market town of Sherborne in
Dorset, where he boarded at Westcott House. The first
day of the term coincided with the 1926 general strike in
Britain, but Turing was so determined to attend that he
rode his bicycle unaccompanied 60 miles from Southampton to
Sherbourne, stopping overnight at an inn. Turing's natural
inclination towards mathematics and science did not earn him
respect from some of his teachers at Sherborne, whose
definition of education placed more emphasis on the classics,
his headmaster wrote to his parents.
I hope he will not fall between two stools. If he is to stay at
public school, he must aim at becoming educated. If he is to
be solely a scientific specialist, he is wasting his
time at a public school.
Despite this, Turing continued to show remarkable ability in
the studies he loved, solving advanced problems in 1927
without having even studied elementary calculus. In 1928, at
age 16, Turing encountered Albert Einstein's work. Not only
did he grasp it, but it is possible that he managed to
deduce Einstein's questioning of Newton's laws of motion from a
text in which was never made explicit. At Sherborne, Turing
formed a significant friendship with fellow pupil Christopher
Morcom who has been described as Turing's "first love". Their
relationship provided inspiration in Turing's future
endeavours, it was cut short by Morcom's death in February
1930, from complications of bovine tuberculosis, contracted
after drinking infected cow's milk some years previously.
The event caused Turing great sorrow. He coped with his grief
by working that much harder on the topics of science and
mathematics, that he had shared with Morcom. In a letter to
Malcolm's mother, Francis Isabel Morcom, Turing wrote,
I am sure I could not found anywhere another companion so
brilliant, and yet so charming and unconceited. I regarded my
interest in my work and in such things as astronomy, to which he
introduced me as something to be shared with him. And I think he
felt a little the same about me. I know I must put as much energy
if not as much interest into my work as if he were alive,
because that is what he would like me to do.
In 1936, Turing published his paper on computable numbers,
with an application to the Entscheidungsproblem. It was
published in the Proceedings of the London Mathematical Society
journal in two parts, the first on the 30th of November and the
second the 23rd of December. In this paper, Turing
reformulated Gödel's 1931 results on the limits of proof
and computation, replacing Gödel's universal arithmetic
base formal language, with the formal and simple hypothetical
devices that became known as Turing machines. Although
Turing's proof was published shortly after Alonzo Church has
equivalent proof using his lambda calculus, Turing's
approach is considerably more accessible and intuitive than
Church's. It also included a notion of a universal machine,
with the idea that such a machine could perform the tasks
of any other computation machine. According to the Church
Turing thesis, Turing machines and the lambda calculus are capable
of computing anything that is computable. John von Neumann
acknowledged that essential concepts of the modern day
computer was due to Turing's paper. And to this day Turing
machines are essential objects of study in the theory of
computation. On the basis of artificial intelligence, and
is now the foundation for modern computer science. During
the Second World War, Turing was a leading participant in the
breaking of German cyphers at Bletchley Park, the historian
and wartime codebreaker. Asa Briggs has said, "You needed
exceptional talent. You need a genius at Bletchley, and
Turing's was that genius." From September 1938 Turing worked
part time with the Government Code and Cypher school, GC and
CS, the British codebreaking organisation, he concentrated on
cryptanalysis of the Enigma Cypher machine used by Nazi
Germany together with Dilly Knox, a senior code breaker
Enigma machine was a Cypher device developed and used in the
early to mid 20th century to protect commercial diplomatic
and military communication. It was employed extensively by Nazi
Germany during World War Two in all branches of the German
military. The Germans believed incorrectly that use of the
Enigma machine enabled them to communicate securely, and so
enjoy a huge advantage in World War Two. The Enigma machine was
considered to be so secure that even the most top secret
messages were enciphered on it's electrical circuits. Enigma has
an electromechanical rotor mechanism that scrambles the 26
letters of the alphabet. In typical use one person answers
text on the enigmas keyboard, and another person writes down
which of the 26 lights above the keyboard lights up at each key
press. If plain text is entered, the lit-up letters are the encoded
ciphertext. Entering ciphertext transforms it back into readable
plain text. The rotor mechanism changes the electrical
connections between the keys and the lights with each key press.
The security of the system depends on a set of machine
settings that were generally changed daily during the war,
based on secret key lists distributed in advance, and
on other settings that were changed for each message. The
receiving station has to know and use the exact settings
employed by the transmitting station to successfully decrypt
a message. While Germany introduced a series of
improvements to Enigma over the years, and these hampered
decryption efforts to varying degrees. They did not prevent
Poland from cracking the machine prior to the war, enabling the
allies to exploit Enigma in Cypher messages as a major
source of intelligence. Many commentators say the flow of
ultra communications intelligence from the decryption
of Enigma, Lorenz, and other ciphers, shortened the war
substantially, may have even altered its outcome. Soon after
the July 1939 meeting near Warsaw, which the Polish Cypher
bureau gave the British and French details of the wiring of
Enigma machine's rotors and their method of decrypting Enigma
machine's messages, Turing and Knox developed a broader solution.
The Polish method relied on an insecure indicator procedure
that the Germans were likely to change, which they in fact did
in May 1940. Turing's approach was more general, using crib-
based decryption, for which he produced the functional
specification of the Bombe an improvement on the Polish Bomba.
On the fourth of September 1939, the day after the UK declared
war on Germany, Turing reported to Bletchley Park, the
wartime station of GC and CS. By using calculated techniques to
optimise the trial of different possibilities in the
codebreaking process. Turing made an innovative contribution
to the subject. He wrote two papers discussing mathematical
approaches, titled the applications of probability to
cryptography, and a paper on statistics of repetitions, which
were of such value to GC and CS and its successor GCHQ that
they were not released to the UK National Archives until April
2012, shortly before the centenary of his birth.
While working at Bletchley, Turing, who was a talented long-
distance runner occasionally ran the 40 miles to London when he
was needed for meetings, and he was capable of World Class
marathon standards. Turing tried out for the 1948 British
Olympic team, but he was hampered by an injury. His
try-out time, though, for the marathon was only 11 minutes
slower than British silver medallist Thomas Richards Olympic
race time of two hours and 35 minutes. He was also Walton
athletic Club's best runner, a facts only discovered when he
passed the group while running alone. Within weeks of arriving
at Bletchley Park Turing had specified an electromechanical
machine called the Bombe, which could break Enigma more
effectively than the Polish version. The bombe with an
enhancement suggested by a mathematician Gordon Welshman
became one of the primary tools and the major automated one used
to attack Enigma in ciphered messages. The bombe detected when
a contradiction had occurred and ruled out that setting moving on
to the next. Most of the possible settings would cause
contradictions and be discarded, leaving only a few to be
investigated in detail. A contradiction would occur when
an enciphered letter would be turned back into the same plain
text letter, which was impossible with the enigma. The
first bombe was installed on the 18th of March 1940. By late 1941,
Turing and his fellow cryptanalyst Gordon Welshman
Hugh Alexander and Stuart Milner-Barry were frustrated.
Building on the work of the poles they had set up a good
working system for decrypting Enigma signals. Their limited
staff and bombes meant they could not translate all the messages.
In the summer, they had considerable success and
shipping losses had fallen to under 100,000 tonnes a month.
However, they badly needed more resources to keep abreast of
German adjustments. They had tried to get more people and
fund more bombes through the proper channels, but everything had
failed. Early in the war Turing found an attraction for
a fellow colleague called Joan Clarke In 1941. He proposed
marriage to Joan, a fellow mathematician and crypto
analyst. Their engagement was short lived.
I suppose the fact I was a woman made me
different. We did do some things together, perhaps went to the
cinema and so on. But certainly it was a surprise to me when he
said, I think his words probably were would you consider marrying
me? But although it was a surprise, I really didn't
hesitate in saying yes. And then he knelt by my chair, and kissed me
we didn't have very much physical contact. Now next day,
I suppose we went a bit of a walk together. After lunch, he
told me that he had this homosexual tendency. And
naturally, that worried me a bit because I did know that that was
something which was almost certainly permanent. But we carried on.
Turing travelled to the United States in November 1942 and
worked with US Navy cryptanalyst, on the naval
Enigma and bombe construction in Washington. He also visited
their computing machine laboratory in Dayton, Ohio.
During this trip, he also assisted at Bell Labs with the
development of secure speech devices. He returned to
Bletchley Park in March 1943. Following his work at Bell Labs
in the US, Turing pursued the idea of electronic enciphering
of speech in the telephone system. In the latter part of the war,
he moved to work for the Secret Service's Radio Security Service
at Hanslope Park. At the park, he further developed his
knowledge of electronics with the assistance of engineer
Donald Bayley. Together they undertook the design and
construction of a portable secure voice communications
machine, codenamed Delilah. The machine was well intended for
different applications, but it lacked the capability for use
with long distance radio transmissions. And in any case,
Delilah was completed too late to be used during the war.
Between 1945 and 1947, Turing lived in Hampton, London, while he
worked on the design of the ACE the Automatic Computing Engine
at the National Physical Laboratory. Although ACE was a
feasible design, the secrecy surrounding the wartime work at
Bletchley Park led to delays in starting the project, and he
became disillusioned. In late 1947, he returned to Cambridge
for a sabbatical year. In 1948, Turing was appointed reader in
the mathematics department at the Victoria University of
Manchester. A year later, he became Deputy Director of the
computing machine laboratory, when he worked on software for
one of the early stored programme computers, the
Manchester Mark 1. When Turing was 39 years old in
1951, he turned to mathematical biology, finally publishing his
masterpiece the chemical basis of morphogenesis in January
1952. He was interested in morphogenesis the development of
patterns and shapes in biological organisms. Although
published before the structure and role of DNA was understood
Turing's work on morphogenesis remains relevant today and is
considered a seminal piece of work in mathematical biology.
In January 1952, Turing was 39 when he started a relationship with
Arnold Murray, a 19-year-old unemployed man. Just before
Christmas, Turing was walking along Manchester's Oxford Road when he
met Murray just outside the Regal cinema and invited him to
lunch. On 23 January, Turing's house was burgled.
Murray told Turing that he and the burglar were acquainted,
and Turing reported the crime to the police. During the
investigation, he acknowledged a sexual relationship with Murray.
Homosexual acts were criminal offences in the United Kingdom
at that time, and both men were charged with gross indecency
under Section 11 of the criminal law Amendment Act of 1885.
Initial committal proceedings for the trial were held on the
27th of February, during which Turing's solicitor "reserved
his defence", which meant he, did not argue or provide evidence
against the allegations. Turing was later convinced by
the advice of his brother and his own solicitor, and he
entered a plea of guilty. The case Regina versus Turing and
Murray was brought to trial on the 31st of March 1952. Turing
was convicted and given a choice between imprisonment and
probation. His probation would be conditional on his agreement
to undergo hormonal physical changes designed to reduce
libido. He accepted the option of injections of what was then
called stilboestrol, a synthetic oestrogen; this feminization of
his body was continued for the course of one year. The
treatment rendered Turing impotent and caused breast
tissue to form, fulfilling in the literal sense Turing's
predictions that "no doubt I shall emerge from it all a
different man, but quite who I've not found out". Murray was
given a conditional discharge. Turing's conviction led to the
removal of his security clearance and barred him from continuing
with his cryptographic consultancy, the government
communication headquarters GCHQ, the British signals
intelligence agency that had evolved from GC and CS in 1946,
though he kept his academic job. He was denied entry into the
United States after his conviction in 1952, but was free
to visit other European countries. Turing was never
accused of espionage but, in common with all who had worked at
Bletchley Park. He was prevented by the Official Secrets Act from
discussing his war work.
On 8 June 1954, Turing's housekeeper found him
dead at the age of 41, he had died the previous day. Cyanide
poisoning was established as the cause of death when his body was
discovered, an apple lay half-eaten beside his bed, and although the
apple was not tested for cyanide, it was speculated that
this was the means by which Turing had consumed a fatal
dose. Turing's remains were cremated at Woking Crematorium
on the 12th of June 1954. And his ashes were scattered in the
gardens of the crematorium, just as his father's had been.
Alan Turing's work did not really come to prominence until
after his death. The man's impact on today's society should
be celebrated and commemorated. Although the highest award
within the computer science industry is still credited to
him. He was a genius, an eccentric and a brilliant
mathematician, and Turing excelled in so many ways. His
work at Bletchley Park has been credited with helping to shorten
the war by as much as two years and helping to save countless
lives. As a pioneer of computer science and artificial
intelligence, Turing remains a complete one off, a man whose
attributions and skills are mind blowing, and yet intoxicating to
study. He was banished from society for being gay and
suffered terrible retribution. Yet this icon will always be
remembered for his contribution to the modern world. And its
advancements. Mark Carney who was governor of the Bank of
England summed up Turing by saying Turing is a giant on
whose shoulders so many now stand.
I hope you enjoyed the story. But wait to learn more, you
really need to check out this video and then this one up here
and benefit today by subscribing. Oh, and well. I'll
see you again soon here on the History Roadshow.