With this mission things are gettin harder cause now network security sam is using an encryption algorithme, and to bypass his brand new security measure we have to decipher the encrypted password. to help us in our task we have a working cipherer make thing easier.
the first thing that some of you may notice is that they have said that “the encryption system is publically available”, we suppose that it’s a well known one, indeed, cause the enryption algorithme is called “caesar” (for more informations about this one, check wikipedia’s entry) but with a minor change, cause the encryption key is variable, it is the place number that a letter occupies within our string, Ithink that an example would clafiry things better:
With the original caesar cipher and an encryption key of 3:
original string : abcd123
encrypted string : defg456
With the one used in HTS:
original string : abcd123
encrypted string :aceg579
How ?
Since “a” was in the 1st place the key is “0″ which means : no subtitution.
And “b” which was in the 2nd place the key is “1″ which means: “b” moved by +1 = “c”.
finally “c” which was in the 3rd place, the key is “2″ which means: “c” moved by +2 = “e”.
and so on for the other letters and numbers.
Decoding the encrypted password “d4e98i6>“:
“d” remains “d ” (remember the key is zero)
“4″ moved by “-1″ will give a “3″
“e” moved by “-2″ will give a “c”
“9″ moved by “-3″ will give a “6″
“8″ moved by “-4″ will give a “4″
“i” moved by “-5″ will give a “d”
“6″ moved by “-6″ will give a “0″
“>” moved by “-7″ will give a “7″ (Check ASCII’s Wikipedia entry)
the Decrypted password is “d3c64d07“
Once again we have defeated Sam at his own game. after deciphring the encrypted password, all we have to do now is to enter it and welcome to the 7th mission.
