Longer means harder to guess
Name:
Date:
Class:
A
Quick Questions
Shade in the A or B circle for each question.
1. A 3-digit code (000 to 999) has 1,000 possible combinations. How many does a 4-digit code have?
2. Which secret is harder to guess?
3. What happens to the number of combinations each time you add one more character?
4. Which password would take a guesser longer to crack?
5. A computer can try thousands of guesses every second. Which is the safer choice?
B
Match the Pairs
Draw a line connecting each item on the left to its match on the right.
| Left column | Right column | |
|---|---|---|
| 13-digit code: 000 to 999 | AComputers can guess very fast, so a short password with few combinations can be found quickly. | |
| 24-digit code: 0000 to 9999 | BEach extra digit multiplies the combinations by 10, so it is 10 times harder, not just a little harder. | |
| 3A longer password has many more combinations, so it takes a computer much longer to guess. | CThere are 1000 possible codes. A guesser has 1000 combinations to try. | |
| 4A short password has few combinations, so a fast computer can guess it very quickly. | Dcat12 | |
| 5A 4-digit code is only a little harder to guess than a 3-digit code. | EThere are 10000 possible codes. That is 10 times more combinations than a 3-digit code. | |
| 6Computers guess slowly, so a short password is safe enough. | Fblue-tiger-jumps-high-87 |
C
Definitions
combinations
D
Fill in the Blanks
Complete each line of code by filling in the missing parts.
1.
combos = __ ** 3
print(combos)
2.
small = 10 ** 3
big = small _ 10
print(big)
3.
small = 10 ** 3
big = 10 ** 4
print(big _ small)
4.
length = 8
combos = 26 ** ______
print(combos)
5.
combos = 26 ** 8
speed = 1000000
seconds = combos / _____
E
Spot the Error
Shade in the letter of the line that contains an error.
Question 1
A
codes3 = 10 ** 3
B
codes4 = 10 ** 4
C
extra = codes4 - codes3
D
print(extra)
Question 2
A
length = 4
B
combos = 10 * length
C
print(combos)
Question 3
A
short = 26 ** 4
B
long = 26 ** 8
C
print(long < short)
Question 4
A
for length in range(3, 6):
B
combos = length ** 10
C
print(length, combos)
Question 5
A
password = 'cat'
B
total = 26 ** password
C
print(total)
Answer Key
Longer means harder to guess
Section A: Quick Questions
Q1
A — 10,000 combinations
Q2
B — A 4-digit code
Q3
A — It multiplies, so there are many more combinations
Q4
B — purple-tiger-bike-cloud
Q5
A — A long passphrase
Section B: Match the Pairs
Q1
3-digit code: 000 to 999 → There are 1000 possible codes. A guesser has 1000 combinations to try.
Q2
4-digit code: 0000 to 9999 → There are 10000 possible codes. That is 10 times more combinations than a 3-digit code.
Q3
A longer password has many more combinations, so it takes a computer much longer to guess. → blue-tiger-jumps-high-87
Q4
A short password has few combinations, so a fast computer can guess it very quickly. → cat12
Q5
A 4-digit code is only a little harder to guess than a 3-digit code. → Each extra digit multiplies the combinations by 10, so it is 10 times harder, not just a little harder.
Q6
Computers guess slowly, so a short password is safe enough. → Computers can guess very fast, so a short password with few combinations can be found quickly.
Section C: Definitions
Q1
combinations — The number of possible guesses for a secret. Each extra character multiplies them, so longer passwords take much longer to guess, even for fast computers.Section D: Fill in the Blanks
Q1
combos = 10 ** 3
print(combos)Q2
small = 10 ** 3
big = small * 10
print(big)Q3
small = 10 ** 3
big = 10 ** 4
print(big > small)Q4
length = 8
combos = 26 ** length
print(combos)Q5
combos = 26 ** 8
speed = 1000000
seconds = combos / speedSection E: Spot the Error
Q1
C — To see how many times more codes a 4-digit code has, divide: codes4 // codes3 gives 10. Subtracting only gives the gap between the two numbers, not how many times bigger it is.
Q2
B — Each extra digit multiplies the combinations by 10, so we need the power operator: 10 ** length. Using * only gives 40, not 10000.
Q3
C — A longer password has more combinations than a shorter one, so long > short should be True. The < sign checks the wrong way round and would print False.
Q4
B — The base (10 digits to choose from) stays the same and the length is the power: 10 ** length. Swapping them gives the wrong numbers and hides how fast combinations grow.
Q5
B — The power must be the number of characters, which is len(password). A word cannot be used as a power, so this causes an error.