Jacques Stern recounts the history of cryptology, from its early days as an arcane activity relegated to the hidden world of defence and diplomacy, to its present-day invasion of our daily lives, through microchips, cellular phones, electronic bank transfers, the Internet, etc. He demonstrates that cryptology and data processing are intimately linked, since both may be regarded as sciences of coding and decoding messages.
However, for the author the primary innovation is theoretical. Has cryptology grown from an unsophisticated `cottage industry' to become a major mathematical discipline? Following an examination of the notions of truth and proof, the author argues that the `science of secrecy' inevitably leads to a reconsideration of the theory of knowledge.