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forward slash radio for I hope you enjoy the program hello in October

1586 in the forbidding hall of Fotheringay Castle, Mary Queen of Scots was on trial for her life,

accused of treason and denied legal representation, she sat alone in the shadow of a vast and

empty throne belonging to her absent cousin,

an arch rival Elizabeth I of England.

Walsingham, Elizabeth's principal secretary, had already arrested and executed Mary's fellow conspirators, her only hope lay in the code

she'd used in all her letters concerning the plot.

If her cipher remained unbroken, she might yet be saved. Not for the first time, the life of an individual

and the course of history depended on the arcane art of cryptography. What are the origins

of this secretive science and what links the Caesar cipher with the complex algorithms which underpin so much of our modern age?

With me to discuss the history of cryptography are Simon Singh, science writer and author of the code book, the secret. of Mary and Professor Fred Piper, director of the Department of Information Security at Royal Holloway University of London.

Simon Singh, can you tell us how secret messages were communicated before the inventions of the first forms of

prectography. What were the early examples of what we call

stegonography and what is that?

...