Intelligence Department

The Intelligence Department is the powerful but institutionally elusive intelligence organization behind the novel’s secret cryptographic work. Its authority reaches into recruitment, private correspondence, movement, and family life, while its exact place in the machinery of government remains deliberately unclear.

Mandate and Institutional Identity

The Intelligence Department appears through its connection to Unit 701, where cryptographers work on ciphers of national importance. In 1956, Rong Jinzhen is taken from his university at dawn after being recruited by Zheng the Gimp, who is revealed to be the head of Unit 701’s cryptography section and Rong’s immediate superior. The transfer is concealed: during the previous day’s hiring process, Rong is made to wear dark glasses, and the repeated turns of the car leave him believing he has remained within the city. The next morning, the car reaches a national highway. The secrecy is not incidental to the job; it is part of the institution’s first claim upon him.

The department’s formal jurisdiction is never settled. An account of Unit 701 notes that its employees dress mostly in civilian clothes, its car park contains both civilian and military vehicles, and questions about whether it belongs to the military, the police, or local government are met with warnings not to ask—or with claims that the respondents do not know. The uncertainty makes the organization difficult to place even for people inside its world. Its practical legitimacy is offered instead as a matter of national necessity: the country requires an agency of this kind, regardless of which branch formally houses it.

Security as Daily Practice

Unit 701’s secrecy is enforced through overlapping controls. Rong’s supposed local destination proves to be a post-box address, and the route to his new workplace is obscured before he is taken beyond the city. Once hired, he is required to swear an oath; when questioned about where he went, his belief that he had stayed in the city is treated as a breach of that oath. The exchange makes even innocent ignorance subject to institutional discipline.

The organization’s secure spaces are guarded in layers. An escorted visitor passes three checkpoints before reaching the complex’s most protected area: first armed police, then guards from the People’s Liberation Army behind barbed wire, and finally a plainclothes guard carrying a walkie-talkie. The mixed uniforms and forms of authority mirror the uncertainty about Unit 701’s official affiliation, while the checkpoints make its operational priority unmistakable: access is controlled before a visitor reaches the work itself.

Control extends into correspondence. When Jan Liseiwicz writes to Rong, the letter follows the ordinary route to Unit 701, but ordinary personal mail is not private there. The surveillance team opens the English-language letter, treats its unfamiliar language as cause for heightened suspicion, reports it to its head, and requests a translation. Whether Rong may read it depends on the letter’s contents. The episode shows the department’s security system operating not only at gates and hiring desks but at the point where one person tries to reach another.

Cryptographic Work and Its Dependencies

The department’s work is shaped by the special difficulty of high-level cryptography. The usual method described in the novel is gradual elimination: intelligence agents collect relevant information, and cryptographers use it to form hypotheses, testing possible keys and structures against the available material. Though laborious, this method is presented as comparatively safe and effective, particularly against sophisticated ciphers. The image of constructing keys and doors captures the scale of the search, but also its dependence on whatever information the organization can gather.

Unit 701’s cryptographic achievements create their own vulnerabilities. After the organization cracks PURPLE, its adversary becomes more careful, reducing the slips of information that might reveal a cipher’s structure. Meanwhile, Rong’s prolonged failure to find an error in BLACK raises the possibility that its makers have adapted to his known abilities. The account considers whether Liseiwicz, who understood Rong’s strengths, could have warned the cipher’s creators and helped them prepare countermeasures. The former closeness between teacher and student is set against the political and intellectual distance that now separates them; intelligence work turns knowledge of a person into a possible advantage for an adversary.

The Intelligence Department’s leadership is shown as closely invested in the outcome. At a conference, the head of the Intelligence Service is described as intensely concerned about progress against BLACK and what would follow its solution. The attention weighs on Rong but also spurs him onward. At a reception, the head promises him a sophisticated calculator capable of more than 40,000 calculations, a gift that would function as a powerful technical assistant. Its later use in confirming the solution to BLACK links institutional resources to an individual act of insight: the cipher’s key is zero, and the apparent lock proves to be a false front.

Surveillance, Possession, and Cost

The department’s protection of secrets also creates pressure on the people who serve it. Before a journey, Vasili and the interviewer repeatedly urge Rong to place every sensitive document in a safety-deposit box, including anything that could identify him as an intelligence officer. On the return trip, Rong secures nearly everything—including a book of maxims from the Director-General of the Intelligence Service—but leaves his notebook outside. The account does not explain why. That omission matters because the notebook is not merely a work record to Rong: it is described as the vessel for his soul. The institution’s effort to secure his official identity thus stands beside the one possession he cannot treat as interchangeable with other documents.

The organization’s secrecy has consequences beyond the workplace. After BLACK is broken, the account describes strict house arrest beginning in the second half of 1970; even earlier, after PURPLE was cracked, those involved had been shadowed when they went out and had their telephone monitored. The people subjected to these restrictions lived under partial confinement before it became formal. Liseiwicz later died of illness in 1979. In retrospect, the period of confinement is also when he told his companion much of what had happened, so the same restrictions that narrowed daily life became the setting in which previously withheld history could be recounted.

The Intelligence Department is therefore defined less by a clear organizational chart than by what it can require and control. It can conceal a recruit’s destination, inspect a private letter, regulate access to a complex, and surround cryptographic work with surveillance. Yet its work remains vulnerable to human knowledge, political division, and the unpredictable moment when a cipher yields. The institution seeks to make information secure; the novel shows that the people and relationships on which security depends cannot be sealed away so easily.