The Giant Raft · Chapter
XIII: Is It a Matter of Figures? explained
Judge Jarriquez explains to Manoel the cryptographic principles behind the document, demonstrating that it is based on a numerical cipher where each letter's value changes according to the cipher's digits.
What happens
Judge Jarriquez explains to Manoel the cryptographic principles behind the document, demonstrating that it is based on a numerical cipher where each letter's value changes according to the cipher's digits. Despite his analysis, he admits the difficulty of deciphering it without the key number, leaving Manoel hopeless about proving Joam Dacosta's innocence.
Themes in this chapter
Deception and Truth
The chapter revolves around the struggle to uncover the truth hidden in the cryptogram, with the judge's analysis revealing the difficulty of distinguishing genuine evidence from deception.
Justice and Innocence
Manoel's desperation to prove Joam Dacosta's innocence highlights the theme of justice, as the document holds the key to exoneration but seems indecipherable.
Characters to notice
- Judge Jarriquez
Explains the cryptographic cipher to Manoel, showing his analytical approach and frustration with the puzzle.
- Manoel Valdez
Visits Judge Jarriquez seeking hope for deciphering the document, but leaves feeling hopeless after the judge's explanation.
Key passages
“I began by treating this document in the proper way, that is to say, logically, leaving nothing to chance. I applied to it an alphabet based on the proportion the letters bear to one another which is usual in our language, and I sought to obtain the meaning by following the precepts of our immortal analyst, Edgar Poe. Well, what succeeded with him collapsed with me.”
Judge Jarriquez attempted to decode the document using standard frequency analysis, as Edgar Allan Poe described, but it failed because the cipher changes letters based on a numerical key.
The judge explains his initial method and its failure, referencing Edgar Allan Poe's analytical techniques.
“That simply proves that the basis of the document is a number. It shows a priori that each letter is modified in virtue of the ciphers of the number and according to the place which it occupies.”
The presence of three consecutive h's indicates that the document uses a numerical cipher, where each letter's value shifts based on the cipher's digits and position.
Jarriquez deduces the cryptographic system from the repeated h's in the text.
“Do you not know, young man, that with the ordinary ten ciphers, using all at a time, but without any repetition, you can make three million two hundred and sixty-eight thousand and eight hundred different numbers, and that if you use the same cipher more than once in the number, these millions of combinations will be enormously increased!”
The judge emphasizes the vast number of possible numerical keys, making it nearly impossible to guess the correct one without additional information.
Jarriquez explains the combinatorial challenge of finding the cipher key.