A Safer Login: Hashed Passwords
Python Programming 2 Grades 9–12 3-day lesson 25 deliverables Teach students how a website can check a password in Python without keeping it. Students compare a stolen table of passwords with a stolen table of hashes, then make hashes with hashlib and store only hashes in a dictionary. They write a sign-up and a login that hashes each try, compares it with the stored hash and allows three tries before a lockout.
● Instant download · Lifetime access · Editable & print-ready
Print + digitalPDF, PowerPoint, Word & Google
Answer keysA key for every page
Built-in assessmentExit tickets + lesson quiz
45-minute daysEvery day planned and timed
Short coding levels practice this lesson in CodeGrove, our code lab that runs in the browser. Students write the program, run it and check it, with no account and nothing to install. Use them with the lesson or as practice later.
See the levelsWhat does this lesson cover?
Students may think a site must keep your password to check it. This lesson shows that a login can store only a hash and compare hashes. Students see what a thief would find in each kind of table.
The try-it on Day 1, the lab on Day 2 and the quiz task on Day 3 run online in CodeGrove, our in-browser code lab, so students need a computer or tablet on those days. The Login Desk level practices hashing passwords with hashlib, storing only hashes in a dictionary, and writing a login that compares hashes and allows three tries. CodeGrove is free, with no accounts, sign-ins or installs.
Login Desk
Students write a sign-up that stores only hashes and a login that allows three tries in CodeGrove.
Everything that's included
00 Start Here
- READ FIRST: every file in the lesson and when you use it
- Teacher Guide and Pacing: the plan for each day, what to print and how to grade
- Skills map: which standards each day teaches
01 Present
- One editable PowerPoint deck for all three days, 23 slides, with speaker notes
- Slide script: the speaker notes, printed
- Bell ringers: a short warm-up for each day
02 Student Handouts
- Guided notes: one packet for all three days, in PDF and editable Word. Students fill in the blanks during the slides, with the word bank on the page
- Vocab slip: the lesson's words and what they mean, on one page
03 Labs
- Login Desk: students write a sign-up that stores only hashes and a login that allows three tries in CodeGrove
04 Activities
- What Would a Thief See?: students compare a stolen table of passwords with a stolen table of hashes, on paper with computers closed
- Quiz task: students fix a login bug in CodeGrove, working alone, and then take the lesson quiz on paper
05 Assessment
- Exit tickets: quick questions that show who needs more help
- Lesson quiz: 8 multiple-choice questions and 2 written answers about all three days, on paper
06 Answer Keys
- 5 answer key files: a key for each day (its bell ringer, notes and exit ticket) and the activity and lab keys, plus the quiz key
Digital: Google Forms™ + Google Slides™
- 4 Google Forms™ of the exit tickets and the quiz, ready to copy into your Drive
- The multiple choice grades itself, and you grade the written answers
- A Google Slides™ copy of the deck, with the same slides and speaker notes, for Google Classroom™
- Give a Form that asks students to read code only on school-managed Chromebooks in locked mode, and use the paper version on other devices
Online: CodeGrove
- In CodeGrove: the lab on Day 2 (Login Desk) and the quiz task on Day 3, on a computer or tablet for each student
- A try-it on Day 1: students practice the new code in CodeGrove, and nothing is turned in
- Free to use, with no accounts, sign-ins or installs
Why teachers love this lesson
A hash goes one wayThe same text always gives the same hash, so a login can compare hashes. A thief who steals the table gets hashes instead of passwords.
A counter adds a lockoutStudents write a login with a counter that allows three tries, and break ends the loop when a try is right. They also learn that real sites add a salt and use a slow hash.
Print and digitalEvery page is a print-ready PDF, and the Google Forms™ and Google Slides™ let you teach the same lesson in Google Classroom™.
Real online labsStudents write and run real Python in CodeGrove, our in-browser code lab, on a computer or tablet, with no accounts or installs.
A key for every pageEvery day has its own answer key, and every written question has a sample answer and what to look for.
Every day fits a 45-minute classEach day's plan is timed activity by activity against real reading and writing speeds.
What Teachers Say
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Leave a reviewQuestions teachers ask
How do I get the files after I buy?
Instant download right after checkout: PowerPoint and Word files you can edit, print-ready PDFs, and links that copy the Google Forms™ and Google Slides™ into your Drive.
Can I buy the whole unit or course instead?
Yes. This lesson is part of the Unit 4 bundle and the complete Python Programming 2 course. Both cost less than buying the lessons one at a time.
Is this AP Computer Science?
No. It is a full-year, non-AP second course in Python for grades 9 to 12. For AP, see our AP Computer Science A and AP CSP courses.
What should students know before this lesson?
Students know try and except, how to check input, and how to count tries in a while loop.
Do students need computers?
Yes, on the CodeGrove days. Each student needs a computer or tablet that's online, and CodeGrove needs no account or install. The bell ringers, notes, exit tickets and quiz are on paper.
What formats are the files in?
Every page is a print-ready PDF. The slides are an editable PowerPoint and the guided notes an editable Word file. The exit tickets and the quiz also come as Google Forms™, and the deck as Google Slides™.
Which standards does it cover?
Written for Florida's Intermediate Programming course (9007220). The skills map in the lesson shows which standards each day teaches.