An encryption system has been set up, which uses an unknown algorithm to change the text given. Requirements: Persistence, some general cryptography knowledge.
Level 6
Network Security Sam has encrypted his password. The encryption system is publically available and can be accessed with this form:
Please enter a string to have it encrypted.
___________________
|___________________|
encrypt
You have recovered his encrypted password. It is:
052g:<8:
Decrypt the password and enter it below to advance to the next level.
Password:
___________________
|___________________|
submit
Solution:
- First, you already got the encrypted password.
052g:<8:
- Then, you should find out the rules of this encryption algorithm.
Use this ASCII Table and make your input password encrypted
http://www.asciitable.com/index/asciifull.gif
You will get 'abcd' should be stored as 'aceg', and '1234' should be stored as '1357' - Finally, you got the rules of the algorithm, which the character's position in the password means how many times the character will be shifted. For example,the inputed password 'abcd'
a is in the 0 position, a will be shifted at 0 time, a->a.
b is in the 1 position, b will be shifted at 1 time, b->c.
c is in the 2 position, c will be shifted at 2 times, c->e.
d is in the 3 position, d will be shifted at 3 times, d->g, etc. - After all, if you encrypt '040d6723', you will see there's the text on the page.
Your encrypted string is: '052g:<8:'
- Submit the password
- Congratulations, you have successfully completed basic 6!
