-1
$\begingroup$

One day ago,i downloaded a pdf that requires password then i search a software to decrypt the password that's s/w called pdfcrack Then i install pdfcrack and run a cmd in terminal pdfcrack -f encrypted.pdf then it shows a some of sentences like that "Average Speed:13343.1 w/s. Current Word: 'txgeg'. " My doubt is when it completes in days or months or years

$\endgroup$
  • 4
    $\begingroup$ Depends on the password. If it's a good password it should never finish. $\endgroup$ – CodesInChaos Apr 17 '16 at 10:37
  • 1
    $\begingroup$ @CodesInChaos "never" is a bit too strong here. Let's formulate it more accurately: Chances are (if the password is any good or at least somewhat creative) that you won't be alive any longer to witness the end of the operation. $\endgroup$ – SEJPM Apr 17 '16 at 13:00
  • $\begingroup$ @SEJPM unless he is considering that the machine will die before the process has finished... :D $\endgroup$ – Hilder Vítor Lima Pereira Apr 19 '16 at 13:10
0
$\begingroup$

Since it uses 128-bit encryption, there are at most $2^{128}$ keys. So if the password is complex enough, you will need on average $2^{127}$ tries. Which is about $1.28×10³⁴$ seconds, or so long that yon can't live that long.

$\endgroup$

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.