Equal passwords still store different values | Rapid course Cryptography and trust services

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Lesson map

Lesson 08. Map, example, EX054.

flowchart TD
  A["Two synthetic accounts, one password"] --> B["same stored value? False"]
  B --> C["Right checks True, wrong check False"]
  C --> D["Do not copy the laboratory secrets into notes"]

A shared password in the script is not a shared stored value, and it is not a library secret to write down.

Logical drawing

stored-value line stays False
right-password lines stay True and True
wrong-password line stays False
notes
    no copy of those laboratory passwords

Learning outcomes

After this chapter, you should be able to:

Keep all four salted-storage lines.
Explain False on the "same stored value" line.
Leave the laboratory passwords out of the library notes.

8.1 Four lines, none of them a member's secret.

lab_salted.py stores one synthetic password for two accounts and prints same password, same stored value? False. The next two lines say member 1 right password: True and member 2 right password: True. The last line says member 1 wrong password: False. A salt is a fresh random value per account, so equal passwords need not produce equal stored results, and the check repeats the calculation rather than looking up a saved password. A classmate who wants the first line to say True is erasing the salt. A classmate who pastes the script's passwords into the staff notes is breaking the sticky-note rule: record place and kind, not the secret itself. These four lines are a teaching run. They are not credentials Leo found at Willow Lane. He does not retune n, r, p, or the salt length.

8.2 Worked example

Lesson table; scroll horizontally to read all columns →

What someone cites	What the file holds	Decision
`same stored value? False`	Different salts	Keep False
Both right-password lines	True and True	Keep both
The wrong-password line	False	Keep False
"Copy the script passwords into the notes."	Secrets stay out of notes	Refuse

Synthetic case. The accounts in this run are not library members.

Errors and limits

Refusing to copy the passwords does not change the four printed Booleans.

Apply

EX054 — Same value? Two synthetic accounts use the same password. The first printed line asks whether the stored values match. What does the file say, and may those passwords be copied into the library notes?
Show marking criteria
Rubric: 3 = the stored values differ, so the line stays False; both right-password lines stay True; the wrong-password line stays False; do not copy the laboratory passwords into the notes; do not edit lab_salted.py;; 2 = False stays and the notes stay clear;; 1 = one line;; 0 = none.