Dan Brown - Digital Fortress / Ψηφιακο Οχυρο

Digital Fortress is a techno-thriller novel written by American author Dan Brown and published in 1998 by St. Martin's Press. The book explores the theme of government surveillance of electronically stored information on the private lives of citizens, and the possible civil liberties and ethical implications using such technology.

Plot summary

When the United States' National Security Agency's code-breaking machine (TRANSLTR) encounters a mysterious and ingeniously complex code called Digital Fortress that it cannot break, Commander Trevor Strathmore calls in Susan Fletcher, a brilliant mathematician and their head cryptographer, to crack it. She discovers that it was written by Ensei Tankado, a former NSA employee who became displeased with the NSA's intrusion into people's private lives. Tankado intends to auction the code's algorithm on his website and have his partner, North Dakota, release it for free if he dies. Essentially holding the NSA hostage, the agency is determined to stop Digital Fortress from becoming a threat to national security.
When Tankado indeed dies in Seville, Spain, of what appears to be a heart attack, Strathmore sends David Becker (Susan's fiancee) to Seville to recover the ring Tankado was wearing when he died. The ring is rumored to have the code that unlocks Digital Fortress. However, he soon discovers that Tankado gave the ring away immediately before his death. Each person that Becker questions in the search for the ring is murdered one-by-one by Hulohot, a mysterious assassin.
Meanwhile, telephone calls between "North Dakota" and Numataka (chairman of a large computer company in Tokyo, Japan) reveal that North Dakota hired Hulohot to kill Tankado in order to gain access to the passcode on his ring and speed up the release of the algorithm. At the NSA, Fletcher's investigation leads her to believe that Greg Hale, a fellow NSA employee, is North Dakota. Phil Chartrukian, an NSA technician, conducts his own investigation into whether Strathmore allowed Digital Fortress to bypass Gauntlet (NSA's virus/worm filter). However, Chartrukian is murdered in the sub-levels of TRANSLTR by an unknown assailant. Since Hale and Strathmore were both in the sub-levels, Fletcher assumes that Hale is the killer; however, Hale claims that he witnessed Strathmore killing Chartrukian.
Hale holds Fletcher and Strathmore hostage to prevent himself from being arrested for the murder. It is then that Hale explains that the e-mail he supposedly "received" from Tankado was actually in his inbox because he was snooping on Strathmore, who was also watching Tankado's e-mail account. After the encounter, Hale's name is cleared when Fletcher discovers through a tracer that North Dakota and Ensei Tankado are actually the same person. Strathmore's role as the primary antagonist is revealed when Strathmore fatally shoots Hale, and arranges it to appear as a suicide. Susan later discovers through Strathmore's pager that he is the one who hired Hulohot. Becker later kills Hulohot in a violent confrontation.
Chapters told from Strathmore's perspective reveal his motives. By hiring Hulohot to kill Tankado, having Becker recover his ring, and having Hulohot kill him, he would be able to have a romantic relationship with Fletcher and also be able to unlock Digital Fortress. By making phone calls to Numataka impersonating as "North Dakota", he thought he could partner with Numataka Corporation to make a Digital Fortress chip equipped with his own backdoor Trojan so that the NSA can spy on every computer equipped with these chips. However, Strathmore didn't know that Digital Fortress is actually a computer worm once unlocked, "eating away" at the NSA databank's security and allowing "any third-grader with Internet access" to look at government secrets. When TRANSLTR overheats, Strathmore commits suicide by standing next to the machine while it explodes. Eventually, the NSA disables the worm before the databank is made accessible to the public. The NSA allows Becker to return to the United States, reuniting him with Fletcher.

Το Ψηφιακό Οχυρό είναι ένα από τα καλύτερα και ρεαλιστικότερα τεχνολογικά θρίλερ που κυκλοφόρησε ποτέ. Γραμμένο από τον πιο πολυδιαβασμένο συγγραφέα παγκόσμια τα τελευταία χρόνια, θα κερδίσει κάθε είδους αναγνώστη με την πλοκή και την αιχμηρότητά του. Η Εθνική Υπηρεσία Ασφάλειας των ΗΠΑ έχει στα χέρια της ένα υπερόπλο στο χώρο των επικοινωνιών: τον παντοδύναμο υπολογιστή TRANSLTR, ο οποίος παρακολουθεί όλο τον πλανήτη και μπορεί να αποκρυπτογραφήσει άμεσα οποιοδήποτε κωδικοποιημένο μήνυμα. Τα προβλήματα ωστόσο ξεκινούν όταν ένας πρώην υπάλληλος της υπηρεσίας αντιτάσσεται στην πρακτική της να παρακολουθεί κάθε πολίτη και δημιουργεί έναν κώδικα απροσπέλαστο, ακόμη και από τον υπερυπολογιστή. Η Εθνική Υπηρεσία Ασφάλειας βρίσκεται σε ομηρία.
O κώδικας έχει τέτοια δύναμη, που μπορεί να καταστρέψει όλο το δίκτυο αντικατασκοπίας. Τότε τη λύση καλείται να δώσει η γοητευτική Σούζαν Φλέτσερ, η ικανότερη κρυπταναλύτρια που διαθέτει η υπηρεσία. Αυτό που ανακαλύπτει θα προκαλέσει τριγμούς σε όλη την ιεραρχία της εξουσίας και θα θέσει σε κίνδυνο ακόμη και τη ζωή της. Αντιμέτωπη με δυνάμεις που την υπερβαίνουν, θα αγωνιστεί με μόνο όπλο το μυαλό της να σώσει τη χώρα από μια σκοτεινή συνωμοσία. «Ψηφιακό Οχυρό», είπε ο Στράθμορ. «Έτσι το ονομάζει. Πρόκειται για το απόλυτο αντικατασκοπικό όπλο. Αν το πρόγραμμα αυτό βγει στην αγορά, κάθε παιδάκι δημοτικού που έχει πρόσβαση σε ένα μόντεμ θα μπορεί να στέλνει κώδικες τους οποίους η NSA δε θα μπορεί να σπάσει. Το σύστημα συλλογής πληροφοριών της χώρας θα καταρρεύσει».