The hours strings still print match False | Rapid course Cryptography and trust services

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Lesson map

Lesson 07. Map, example, EX053.

flowchart TD
  A["Two synthetic hour strings"] --> B["match: False"]
  B --> C{"Did the library change its hours?"}
  C -->|No| D["Keep the strings and False"]
  C -->|Yes| E["No timetable decision is filed"]

The inputs are laboratory text. They are not a new opening-hours policy.

Logical drawing

string A ends 9-17
string B ends 9-18
prints
    A: 7a5d91566f93af7abf7fc2c33d868004...
    B: c029501271e71ec3fc765840b69dfabd...
    match: False
library timetable
    not stated by those strings

Learning outcomes

After this chapter, you should be able to:

Keep the two hour strings and match: False.
Keep each printed prefix with its dots.
Refuse to treat the strings as the library's timetable.

7.1 One character apart, and still not a policy.

The fingerprint script sets string A to Willow Lane opening hours: 9-17 and string B to Willow Lane opening hours: 9-18. The embedded output shows A: 7a5d91566f93af7abf7fc2c33d868004..., B: c029501271e71ec3fc765840b69dfabd..., and match: False. Each print is a 32-digit prefix plus dots, just as ha[:32] and hb[:32] are written. A classmate who needs a tidy story says the library now closes at 18:00, or edits the script until the match line says True. The book never states the library's real hours. The two strings exist so a single character change can be seen. Leo leaves False on the page and does not promote either string into a timetable decision.

7.2 Worked example

Lesson table; scroll horizontally to read all columns →

What someone cites	What the file holds	Decision
String A ending `9-17`	Laboratory input	Keep the input
String B ending `9-18`	Laboratory input	Keep the input
`match: False`	Embedded output	Keep False
"The library adopted 9-18."	No hours decision	Refuse

Synthetic case. The hour strings are inputs to a hash. They do not set the door time.

Errors and limits

Leaving False in place does not hide that the prefixes differ. It refuses a True the script did not print.

Apply

EX053 — New hours? The laboratory strings end 9-17 and 9-18, and the output says match: False with the two published prefixes. May Leo report that Willow Lane changed its opening hours?
Show marking criteria
Rubric: 3 = no; both strings stay; both prefixes stay with their dots; match: False stays; the strings are not a timetable; do not edit lab_fingerprint.py;; 2 = False stays and the hours are not a policy;; 1 = one prefix;; 0 = none.