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Members of a certain website are required to select password
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27 Dec 2019, 11:27
27 Dec 2019, 11:27
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Question Stats:
76% (01:40) correct
23% (02:38) wrong based on 17 sessions
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Members of a certain website are required to select passwords that are exactly six characters long. The first four characters may be selected from any of the 26 letters from A to Z (not case-sensitive) or any of the digits 0-9, but the last two characters of the password must be selected from only the digits 0-9. For Instance, abcd45, 8hi976. and 5dog56 are valid passwords. A hacker writes a computer program mat will test every permissible password combination at a rate of 72 passwords per second. How long, IN HOURS, will it take the hacker's program to test every permissible password combination?
A. 18
B. 62
C. 648
D. 1,080
E. 38,880
Kudos for the right answer and explanation
A. 18
B. 62
C. 648
D. 1,080
E. 38,880
Kudos for the right answer and explanation
Re: Members of a certain website are required to select password
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29 Dec 2019, 12:02
29 Dec 2019, 12:02
1
This is a fun one!
First step - need to figure out how many possible passwords there are.
You have 6 positions to fill, so draw out _ _ _ _ _ _
The first 4 can be filled with any letter, or any digit from 0 - 9. There are 26 letter options, and 10 digit options = 36 total options for each space. The last 2 can ONLY be a digit from 0-9, so the last two spaces only have 10 options for each.
_ _ _ _ _ _
36 36 36 36 10 10
To figure out how many total possibilities there are, multiply all those numbers together: 36*36*36*36*10*10 = 167,961,600 total password possibilities
Now, a hacker is going to try to brute force his way in by trying EVERY possible password. Their program can test 72 passwords per second. So, take the total possible passwords and dive by 72 to see how many seconds it'll take the hacker to try all the possibilities.
167,961,600 / 72 = 2,332,800 seconds.
BUT, the question asks how many HOURS!
Convert the 2,332,800 seconds to minutes by dividing by 60 (60 seconds per minute) = 38,880. Finally, divide that by 60 to get the number of hours (60 minutes / hour)
38,880 / 60 = 648. Answer is C - it'll take the hacker 648 Hours to test every single possible password. Almost a whole month!
First step - need to figure out how many possible passwords there are.
You have 6 positions to fill, so draw out _ _ _ _ _ _
The first 4 can be filled with any letter, or any digit from 0 - 9. There are 26 letter options, and 10 digit options = 36 total options for each space. The last 2 can ONLY be a digit from 0-9, so the last two spaces only have 10 options for each.
_ _ _ _ _ _
36 36 36 36 10 10
To figure out how many total possibilities there are, multiply all those numbers together: 36*36*36*36*10*10 = 167,961,600 total password possibilities
Now, a hacker is going to try to brute force his way in by trying EVERY possible password. Their program can test 72 passwords per second. So, take the total possible passwords and dive by 72 to see how many seconds it'll take the hacker to try all the possibilities.
167,961,600 / 72 = 2,332,800 seconds.
BUT, the question asks how many HOURS!
Convert the 2,332,800 seconds to minutes by dividing by 60 (60 seconds per minute) = 38,880. Finally, divide that by 60 to get the number of hours (60 minutes / hour)
38,880 / 60 = 648. Answer is C - it'll take the hacker 648 Hours to test every single possible password. Almost a whole month!
Re: Members of a certain website are required to select password
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29 Dec 2019, 21:07
29 Dec 2019, 21:07
1
_ _ _ _ _ _
We have to fill these 6 blanks. Also, the examples show that the digits or letters could be repeated.
Now the last two blanks have a restriction that it can only consist of digits. So, there will be 10 choices for each blank
For, the first four blanks we have 36 choices each(26 letters and 10 digits)
Total possible combinations of passwords = \(36*36*36*36*10*10\)
Now the hacker can check 72 passwords per second so it means he/she can check \(72*60*60\) passwords in an hour.
No of hours to check all the passwords = \(\frac{36*36*36*36*10*10}{72*60*60}\) = 648 hours
OA, C
We have to fill these 6 blanks. Also, the examples show that the digits or letters could be repeated.
Now the last two blanks have a restriction that it can only consist of digits. So, there will be 10 choices for each blank
For, the first four blanks we have 36 choices each(26 letters and 10 digits)
Total possible combinations of passwords = \(36*36*36*36*10*10\)
Now the hacker can check 72 passwords per second so it means he/she can check \(72*60*60\) passwords in an hour.
No of hours to check all the passwords = \(\frac{36*36*36*36*10*10}{72*60*60}\) = 648 hours
OA, C
Carcass wrote:
Members of a certain website are required to select passwords that are exactly six characters long. The first four characters may be selected from any of the 26 letters from A to Z (not case-sensitive) or any of the digits 0-9, but the last two characters of the password must be selected from only the digits 0-9. For Instance, abcd45, 8hi976. and 5dog56 are valid passwords. A hacker writes a computer program mat will test every permissible password combination at a rate of 72 passwords per second. How long, IN HOURS, will it take the hacker's program to test every permissible password combination?
A. 18
B. 62
C. 648
D. 1,080
E. 38,880
Kudos for the right answer and explanation
A. 18
B. 62
C. 648
D. 1,080
E. 38,880
Kudos for the right answer and explanation
