The two paths through the forest of cryptography

The two paths through the forest of cryptography are Rong Jinzhen’s way of reading how ciphers change: their outward forms can be transformed, while their internal structures tend toward greater refinement. The theory offers a possible route to decryption through the history of the field, but it also leads directly into the danger cryptographers have long tried to avoid. Its force lies in that contradiction: a method that might illuminate a cipher can also draw its investigator into the very theories and patterns that make clear thinking impossible.

The Two Paths

Rong Jinzhen compares a cipher’s changing outward form to the changing face of a person, but with an important difference. A human face remains a face however it is altered; a cipher has no such fixed parameters. Its outward form could change into something wholly different, while its internal features are refined, clarified, advanced, and made more perfect. In his account, these are not competing explanations of change but two simultaneous processes: transformation of the exterior and development of the interior. Together they make a twin path at the heart of any new cipher.

That distinction gives the theory its practical purpose. If a codebreaker can identify both paths in the history of cryptography, the patterns may offer help in decrypting a modern system. The outward transformation can make one cipher appear unrelated to another; the continuing refinement of internal features offers a possible thread of connection beneath those changes. Rong Jinzhen’s argument is not that ciphers share an obvious surface resemblance. Rather, their histories may disclose processes of development that are less visible than their designs.

While explaining the idea, Rong Jinzhen points to columns of figures covering the room, their dense arrangement compared to a hoard of ants. His finger moves among them and sometimes stops, as if following a route toward the matter’s center. The scene gives the theory a physical form: its two paths are not simply declared, but pursued through accumulated calculations and historical material.

A Dangerous Route Through History

The theory puts Rong Jinzhen in conflict with an unwritten rule of the profession: avoid history. Cryptographers have reason to fear historical concepts and theories, because a compelling precedent can attract the mind and dominate its work. The narrator sees Rong Jinzhen’s proposed route as an attempt to pull on two strings that lead into the accumulated history of cryptography, cutting through layer after layer of ideas in search of underlying principles. Each layer could supply an insight, but each could also become a trap from which the investigator cannot escape.

This danger helps explain why the rule exists despite the potential usefulness of the historical record. Past cryptography may contain pointers to ways of decrypting present-day ciphers, yet entering that forest risks becoming fixated on its theories. A codebreaker may then lose the capacity to approach a new cipher on its own terms. Since ciphers must avoid intrinsic similarity to one another if they are not to become easy to crack, a historical analogy can be both suggestive and misleading. The theory therefore threatens not only the person applying it but also the independence of the cipher under examination.

The narrator treats this prohibition as more than professional caution. The forest of cryptographic history is lonely: its investigators cannot safely ask predecessors for directions or simply build on their work. They must travel by side roads, wary of open paths, and the loss of history’s guidance also means the loss of a shared intellectual inheritance. In this account, the discipline’s isolation is one of its costs. Rong Jinzhen’s theory challenges that isolation by trying to use past work, but it also exposes the peril that produced the rule.

An Unconventional Method and Its Risks

The established approach to decryption is a process of elimination. Intelligence agents gather relevant information; cryptographers form hypotheses and test them, like designing keys for an immense number of doors. The scale of the work depends on how much material is available and on how sensitive the investigator is to the cipher. The narrator characterizes this method as simple and even stupid, but also safe, secure, and effective, particularly for high-level ciphers. It remains in use because its success rate is comparatively high.

Rong Jinzhen does not want to proceed in that conventional way. By immersing himself in cryptographic history, he enters forbidden territory and attempts to narrow the search through inherited patterns. The possible benefit is substantial but uncertain: if a search presented 10,000 byroads, historical reasoning might eliminate half, or fewer. How many routes it actually removed would determine whether the theory could work at all. The narrator stresses that successful practitioners of such a dangerous method are as rare as morning stars. Its risk makes Rong Jinzhen difficult to classify: a lunatic might attempt it without understanding the danger, while a genius might do so knowing that he possesses unusual means to overcome it.

The narrator cannot initially decide which description fits Rong Jinzhen. What becomes clear is that he understands the rule he is breaking. The diagrams on the walls and his engagement with the field’s history suggest not ignorance but deliberate choice. The narrator responds with silent admiration, mixed with jealousy, and regards Rong Jinzhen as far ahead of the others despite his having spent less than six months in the cryptography unit. The theory thus presents intellectual courage and professional risk as inseparable: its author may be opening a route to discovery, or allowing the forest to claim him.

From Theory to Consequence

Rong Jinzhen’s later decryption of the PURPLE cipher gives the theory’s risks a concrete outcome. He cracks it without telling anyone, a result that does not surprise the narrator after the earlier display of his willingness to cross forbidden ground. The narrator feels relief for him as well as astonishment. His achievement makes the theory’s audacity seem less like an abstract provocation, though the account does not establish that the two-paths method alone explains the solution.

The circumstances surrounding PURPLE also show how easily a route toward a cipher can be distorted. After the decryption, the team learns that Jan Liseiwicz’s suggestions for how to solve it were wrong. The team had withheld those suggestions from Rong Jinzhen, and the narrator concludes that this decision may have spared him from following a misleading path. Jan Liseiwicz may have been trying to sabotage the work, or may simply have been making the same mistakes in his own attempts; the narrator considers the latter more likely in light of what the team understood at the time. The episode complicates any simple celebration of historical or expert guidance: an apparent aid can steer a codebreaker away from a solution.

The account later contrasts the success on PURPLE with the prolonged failure to decrypt the BLACK cipher. After PURPLE was cracked, the opposing side became more careful, leaving fewer slips for codebreakers to exploit. The narrator describes the cipher as a seamless net that nevertheless leaks through its use, as speech can betray its speaker; Rong Jinzhen had waited through countless days and nights for such an opening in BLACK without finding one. The eventual key was zero, concealed in the leather attaché case. This discovery does not demonstrate that the two-paths theory directly solved BLACK. Instead, it sharpens the theory’s larger tension: decryption can depend on patterns and accumulated reasoning, but also on recognizing when the apparent lock is only a façade.

Significance

The theory’s forest image joins intellectual possibility to danger. History contains routes that may narrow a search, but those same routes can capture attention, impose false likenesses, and prevent a cryptographer from seeing a new cipher clearly. Rong Jinzhen’s twin paths attempt to preserve a distinction between changing form and refining structure, making historical comparison useful without assuming that ciphers are simply repetitions of one another.

His willingness to test that distinction gives the expression its narrative significance. It anticipates both the risks of his work and the startling success that makes the narrator reconsider what can be attempted. Yet the narrative does not turn the method into a guaranteed key: the warnings against historical entanglement, the misleading suggestions about PURPLE, and the separate, unexpectedly simple key to BLACK all resist that conclusion. The two paths remain a daring way to search, not a promise that the forest will yield its secrets.