St Martin's Press Digital Fortress

When the National Security Agency’s invincible code-breaking machine encounters a mysterious code it cannot break, the agency calls its head cryptographer, Susan Fletcher, a brilliant, beautiful mathematician. What she uncovers sends shock waves through the corridors of power. The NSA is being held hostage…not by bombs but by a code so complex that if released would cripple U.S. intelligence.

Caught in an accelerating tempest of secrecy and lies, Fletcher battles to save the agency she believes in. Betrayed on all sides, she finds herself fighting not only for her country but for her life. It is a battle for survival―a crucial bid to destroy a creation of inconceivable genius that threatens to obliterate the balance of world power…for all time.