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Plot Summary

Digital Fortress

Dan Brown
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Digital Fortress

Fiction | Novel | Adult | Published in 1998

Plot Summary

Digital Fortress (1998), a techno-thriller novel by American author Dan Brown, concerns the events that take place after an advance in cryptography foils the secret government supercomputer, TRANSLTR, which has been used to violate Americans’ privacy rights. The novel explores themes of government surveillance, the flow and security of individuals’ private data, and the unintended effects of technological change.

The novel begins as members of the United States’ National Security Agency encounter a piece of code that TRANSLTR is unable to break. Commander Trevor Strathmore reaches out to the NSA’s head cryptographer, Susan Fletcher, asking her to try to break it. After precursory research, Fletcher discovers a former NSA operative Ensei Tankado created the code. Tankado had become disillusioned with the purpose of the NSA after finding that it routinely pries into the private data of citizens without just cause. Tankado presents an ultimatum to the NSA wherein he will reveal his cryptographic code, “Digital Fortress,” to the world via an auction to the highest bidder unless the NSA informs the American public about the nature of TRANSLTR. If he dies, he has a provision in place that allows his partner, who goes by “North Dakota,” to release the code for free. In response, the NSA resolves to stop Digital Fortress through other means.

Tankado is found dead in Seville, ostensibly of a heart attack. Upon Tankado’s death, Strathmore requests that Fletcher’s soon-to-be husband, David Becker, fly to Seville to find a ring that Tankado had worn. The NSA suspects the ring contains a code that will unlock Digital Fortress. Becker investigates, finding that Tankado gave the ring away just before he died. He questions a series of people, who are subsequently murdered by a deaf assassin, Hulohot.



A series of telephone calls take place between Tokugen Numataka and North Dakota. Numataka is the chair of a powerful Japanese computer firm, Numatech. The calls show that North Dakota hired Hulohot to assassinate Tankado to get access to the decryption key on his ring, hoping to send out the algorithm for free without any uncertainty or struggle. Fletcher investigates, suspecting that a current NSA operative Greg Hale is North Dakota.

Meanwhile, NSA technician Phil Chartrukian who is not privy to the investigation of Digital Fortress discovers it independently. Believing that it is a virus, he tries to find out whether Strathmore is complicit in allowing it to pass through the NSA’s Gauntlet, a virus blocker. Before he can draw a conclusion, he is killed by an unknown person in the bowels of the TRANSLTR machinery by being pushed off of a walkway, damaging its cooling system. At the time of his death, both Strathmore and Hale are inside TRANSLTR, causing Fletcher to assume that Hale killed him. On interrogation, Hale insists that Strathmore killed Chartrukian.

Hale holds Strathmore and Fletcher hostage to avoid being incriminated for Chartrukian’s murder. He explains that the initial email from Tankado had reached his inbox only because he was surveilling Strathmore, having learned that Strathmore was observing his data. Hale is exonerated after Fletcher finds out via a tracking device that Ensei Tankado and North Dakota are the same person, realizing that the anagram “NDAKOTA” recombines into “TANKADO.” Strathmore kills Hale and botching an attempt to make it seem like a suicide, reveals himself. Fletcher taps into Strathmore’s pager, finding out that he hired Hulohot. Becker tracks down Hulohot and narrowly survives, killing the assassin.



The remainder of the book tells the story from Strathmore’s angle, revealing his personal motives for carrying out the attack. In love with Fletcher, he had set up the elaborate attack hoping to compel Fletcher to fall in love with him. The plan was supposed to culminate in him becoming a national hero when he unlocked Digital Fortress. He placed a series of phone calls as North Dakota, trying to convince Numataka to create easily hackable Digital Fortress chops so he could spy on anyone. However, he failed to realize that Digital Fortress’s virus was so destructive to computational security systems that it would expose government secrets to anyone with a computer. When TRANSLTR begins to overheat, Strathmore stands next to it, committing suicide when it explodes. Just after the virus reaches the NSA database, Becker discovers that the password is 3, a reference to the bombs that killed Tankado’s mother and crippled him. The NSA permits Becker to come back to the United States, where he reunites with Fletcher.

The crux of Digital Fortress, which comes down to the ego and insecurity of one man, suggests that personal motives are entangled with professional ones, transforming centers of political power into tools for advancing personal agendas. Framing this fact around the modern discourse on whether private citizens should retain rights to data privacy, it is a case against government interference in Americans’ constitutional rights.