Online database servers often generate random passwords which the user must repeat back to the server to confirm that the request is coming from a human user and not a malicious netbot. The systems for two different airlines use variations of this approach:
Pigeon Airlines generates passwords by randomly selecting seven uppercase letters, without using the same letter twice.
Bumblebee Airways randomly selects six uppercase letters, again without duplication, and appends a randomly selected decimal digit.
a. Calculate the number of different passwords that could be generated for each of these two reservation systems.
For Pigeon Airlines - Number of Passwords that can be generated are- **26 X 25 X 24 X 23 X 22 X 21 X 20 = 3515312000** For Bumblee Airlines - Number of Passwords that can be generated are - **26 X 25 X 24 X 23 X 22 X 21 X 10 = 1657656000**
b. If a netbot was to try a brute-force attack on one of these reservation systems by trying to guess the password using random trials, which reservation system would be easier to crack?
Probability to get Pigeon Airlines Correct = 1/3315312000 = 0.00000000030163 Probability to get Bumble Bee Correct = 1/1657656000 = 0.00000000060326 So, it would be easier for him to crack BumbleBee Airlines!
Is my answer correct? Thanks for the help!
Edited my answer to make it more understandable!