Wednesday, 19 February 2014
Digital Fortress - Dan Brown | Free PDF Download Ebook
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.
When the United States National Security Agency's code-breaking supercomputer (TRANSLTR) encounters a new and complex code—Digital Fortress—that it cannot break, Commander Trevor Strathmore calls in Susan Fletcher, 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, "NDAKOTA", 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 does indeed die in Seville, of what appears to be a heart attack, Strathmore asks David Becker (Susan's fiancé) to travel to Seville and recover a ring that Tankado was wearing when he died. The ring is suspected to have the code that unlocks Digital Fortress. However, Becker soon discovers that Tankado gave the ring away immediately before his death. Each person he questions in the search for the ring is murdered by Hulohot, a mysterious assassin.
Meanwhile, telephone calls between "North Dakota" and Numataka (chairman of a large computer company in Tokyo) 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. However, Chartrukian is murdered by being pushed off the catwalk 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. Chartrukian's fall also damages TRANSLTR's cooling system.
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. 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 at the same time arranging for Hulohot to kill him, would facilitate a romantic relationship with Fletcher, regaining his lost honor, and enable him 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 was unaware that Digital Fortress is actually a computer worm once unlocked, "eating away" at the NSA databank's security and allowing "any third-grader with a modem" to look at government secrets. When TRANSLTR overheats, Strathmore commits suicide by standing next to the machine as it explodes. The worm eventually gets into the database, but soon after Fletcher figures out the password (3, the difference between the Hiroshima nuclear bomb, Isotope 235, and the Nagasaki nuclear bomb, isotope 238, a reference to the nuclear bombs that killed his mother and left him crippled), and is able to terminate the worm before hackers can get any significant data. The NSA allows Becker to return to the United States, reuniting him with Fletcher. In the epilogue, it is revealed that Numataka is Ensei Tankado's father. Numataka left Tankado the day he was born since Tankado was a deformed child.
Susan Fletcher — The NSA's Head Cryptographer, and the story's lead character
David Becker — A Professor of Modern Languages and the fiancé of Susan Fletcher
Ensei Tankado — The author of Digital Fortress and a disgruntled former NSA employee. Was disabled and assassinated
Commander Trevor Strathmore — NSA Deputy Director of Operations
Phil Chartrukian — Sys-Sec Technician
Greg Hale — NSA Cryptogropher
Leland Fontaine — Director of NSA
"Hulohot" — an assassin hired by Strathmore to locate the Passkey
Midge Milken — Fontaine's internal security analyst
Chad Brinkerhoff — Fontaine's personal assistant
"Jabba" — NSA's senior System Security Officer
Soshi Kuta — Jabba's head technician and assistant
Tokugen Numataka — Japanese Executive attempting to purchase Digital Fortress.
Real life scenarios
The book is loosely based around recent history of cryptography. In 1976 the Data Encryption Standard (DES) was approved with a 56-bit key rather than the 64-bit key originally proposed. It was widely believed that the National Security Agency had pushed through this reduction in security on the assumption that it could crack codes before anyone else.
In fact the DES was first publicly broken in 1997, 96 days after the first of the DES Challenges. In 1998, the same year as Digital Fortress was published, the Electronic Frontier Foundation (featured in the book) built a piece of hardware costing less than $250,000 called the EFF DES cracker which broke it in 56 hours and by 1999 the record was under 24 hours.
The brute force search used by TRANSLTR takes twice as long for each extra bit added to the key (if this is done sensibly), so the reaction of the industry has understandably been to lengthen the key. The Advanced Encryption Standard established in 2001 uses 128, 192 or 256 bits, which take at least 1021 times as long (i.e. 270) to solve by this technique.
Unbreakable codes are not new to the industry. The one-time pad, invented in 1917 and used for the cold-war era Moscow-Washington hotline, was proved to be unconditionally secure by Claude Shannon in 1949 when properly implemented. However it is inconvenient to use in practice and is limited mainly to military and governments.