Building a passphrase from random words

Name:

Date:

Class:

Quick Questions

Shade in the A or B circle for each question.

1. Which is a better way to build a passphrase?

A Pick three or four random words that do not belong together

B Pick one word that you really love

2. Which passphrase is built from random words?

A my-dog-is-Max

B lamp-frog-cloud-7

3. Where can you find random words to use in a passphrase?

A Use your name, your pet's name and your school

B Look around the room and pick things you can see, like desk, sock and window

4. Which is true about the words in a passphrase?

A Four short words are better than one long word

B One long word is always better than four short words

5. How can you make a passphrase even harder to guess?

A Add a number or symbol between the words, like boat7pizza!tree

B Put the words in alphabetical order with no gaps

Match the Pairs

Draw a line connecting each item on the left to its match on the right.

Left column		Right column
1teapot-87-cloud-sock		AAll the words belong to the same topic, so they are easy to guess. Pick words that are not related.
2pencil+zebra+moon		Bbanana-rocket-sock
3Pick words that do not belong together, like things you spot around the room		Cdog+sky+jam+owl
4Four short words joined together are better than one long word		DA passphrase of three random words joined with plus symbols
5ilovemydog		EA passphrase of four random words joined with a number and a symbol
6sun-moon-star-sky		FThe words make a sentence about you, so people who know you could guess it. Use random words that do not belong together.

Definitions

random words

Fill in the Blanks

Complete each line of code by filling in the missing parts.

passphrase ← word1 _ word2 + word3

phrase ← _____ + "-" + word2 + "-" + word3

words ← ["tiger", "pencil", "cloud"] word1 ← ______(words)

wordCount ← 4 IF wordCount __ 3 THEN PRINT "Good passphrase"

symbol ← "#" passphrase ← word1 + ______ + word2

Spot the Error

Shade in the letter of the line that contains an error.

Question 1

A word1 ← "spoon"

B word2 ← "volcano"

C word3 ← "fork"

D pw ← word1 + word2 + word3

Question 2

A words ← ["pan","owl","sand"]

B count ← 1

C pw ← join(words, "-")

D show pw

Question 3

A w1 ← "frog"

B w2 ← "lamp"

C w3 ← "bus"

D pw ← w1 + "7" + w2

Question 4

A words ← [myName, myPet]

B pw ← join(words, "-")

C show pw

Question 5

A words ← ["cat","mug","sun"]

B count ← length(words)

C if count > 3 then pick more

D join words with "-"

Answer Key

Building a passphrase from random words

Section A: Quick Questions

A — Pick three or four random words that do not belong together

B — lamp-frog-cloud-7

B — Look around the room and pick things you can see, like desk, sock and window

A — Four short words are better than one long word

A — Add a number or symbol between the words, like boat7pizza!tree

Section B: Match the Pairs

teapot-87-cloud-sock → A passphrase of four random words joined with a number and a symbol

pencil+zebra+moon → A passphrase of three random words joined with plus symbols

Pick words that do not belong together, like things you spot around the room → banana-rocket-sock

Four short words joined together are better than one long word → dog+sky+jam+owl

ilovemydog → The words make a sentence about you, so people who know you could guess it. Use random words that do not belong together.

sun-moon-star-sky → All the words belong to the same topic, so they are easy to guess. Pick words that are not related.

Section C: Definitions

random words — To build a passphrase, pick three or four random words that do not belong together and join them. Adding a number or symbol between the words makes it even harder to guess.

Section D: Fill in the Blanks

passphrase ← word1 + word2 + word3

phrase ← word1 + "-" + word2 + "-" + word3

words ← ["tiger", "pencil", "cloud"]
word1 ← RANDOM(words)

wordCount ← 4
IF wordCount >= 3 THEN
    PRINT "Good passphrase"

symbol ← "#"
passphrase ← word1 + symbol + word2

Section E: Spot the Error

C — "fork" belongs with "spoon", so the words are related and easier to guess. Pick random words that do not belong together, like "sock".

B — A passphrase needs three or four random words. One word is too easy to guess, so count should be 3 or 4.

D — This only joins two words and leaves out w3. Join three words, putting a number or symbol between them: w1 + "7" + w2 + "!" + w3.

A — Your name and pet are personal and easy for others to guess. The words should be random, so it should be words ← random(4).

C — The check is the wrong way round. You need to pick more words when count is LESS than 3, so use < not >.