i'am new to perl programming and tiring to implement a function to perform pdf file get encrypted and save in server and pdf encrypted file need to decrypted , when it is downloaded by a authorised user and for rest of the users if they download , it should be in unreadable format.

for implementing the above function, i tried of doing using pdftk and installed PDF::Tk ().

source code: 
use PDF::Tk;
my $doc=PDF::Tk->new();
$doc->call_pdftk('input.pdf', 'outPDF.pdf', 'owner_pw', 'foopass');

[download]
output: Can't find executablable /usr/bin/pdftk at /usr/lib/perl5/site_perl/5.8.5/PDF/Tk.pm line 19.

Does this error mean to set the environment PATH variable to "/usr/bin/pdftk".

Please let me know how to resolve the above issue.

In reply to pdftk functionality by sumalatha

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