From Sixteenth-Century Cryptography to the New Millennium — The Last 500 Years - Codes: The Guide to Secrecy from Ancient to Modern Times - page 74

2.3 Nineteenth-Century Cryptography

Thought can with di E culty visit the intricate and winding chambers which it
inhabits.

Percy Bysshe Shelly (1792-1822)
English poet, husband of Mary Shelly
— from Speculations on Metaphysics (1815)

In the nineteenth century, one man may be said to have been the vision-
ary pioneer when it comes to foreseeing the modern-day automatic electronic
computer, Charles Babbage (1791-1871). Babbage was born in the Walworth,
Surrey area, in London, England on December 26, 1791 to Benjamin Babbage
and Elizabeth Teape. Benjamin was a wealthy banker, who left Charles a size-
able fortune upon his death. This financed his many lifelong interests, from
areas as diverse as archeology, to submarine navigation, mathematics in gen-
eral, and cryptology in particular.
In 1810, he attended Trinity College, Cambridge, and by 1817 had received
his master's degree. In 1816, Babbage was elected as a fellow of the Royal
Society. He had lived at Devonshire Street in London until 1828 when he took up
a position as Lucasian Professor of Mathematics at the University of Cambridge.
Then he moved to 1 Dorset Street, Manchester Square, London, where he lived
until his death. Babbage held the position at Cambridge until 1839.
It was in the mid-1830s that Babbage envisioned a machine (which he called
the analytical engine ) executing arithmetical operations via instructions from
punched cards, having memory to store data, and other fundamental aspects
of modern computers that developed more than a century after he conceived of
them. He started on what he called the Difference Engine Number 1 in 1823,
but abandoned it after a decade of work. By the end of 1834, he had conceived
of his analytical engine, but he began work on a less ambitious project, his
Difference Engine Number 2 . However, the government had been funding his
project from the outset, and by this time with no concrete results, they withdrew
their support, so his design was not completed. Yet, although he never published
his notebooks, they were discovered in 1937. By 1991, at the British Science
Museum, the Difference Engine Number 2 was built to original designs in order
to commemorate the bicentennial of Babbage's birth. It is accurate to 31 digits,
as Babbage had envisioned, and it is the first of his machines to be completed.
Another important factor in Babbage's failure to complete the construction
of any of his devices must certainly have been that the technology of the day
was woefully insuQcient to make the precision parts that his designs required.
That it took roughly 150 years for one of them to be built is probably testimony
to that statement. Although Babbage never completed any of his machines, his
conception of the analytical engine is the vehicle for his fame as a visionary of
the modern digital computer.
More important for us, Babbage is also known for his penetrating crypt-
analytic skills. The Vigenere cipher was considered, up to the mid-nineteenth
century, to be unbreakable, and it achieved the title of the chiffre indechiffrable .
However, in the mid-1850s, Babbage cryptanalyzed the Vigenere cryptosystem.