RC4 is about your easiest encryption. There are alot of others too, RC5, and Rijndael. The biggest problem for beginners is the need to make either the data or key a certain blocksize. Some algorithms don't require this.

Here are a couple of examples: 

#!/usr/bin/perl
use Crypt::RC4;

$passphrase = "rumpelstiltskin";

$plaintext= qw(qqq"""""""''''''';;;;;qwweeerrrtttyyyy); 
 
$encrypted = RC4( $passphrase, $plaintext ); 
$decrypt = RC4( $passphrase, $encrypted ); 
 
print "$plaintext\n$encrypted\n$decrypt\n";

[download]

or 

#!/usr/bin/perl
use Crypt::RC5;

$key = 'e726f4a56b3e4f';
$rc5 = new Crypt::RC5($key, '12' );

open (FH,"< /etc/passwd");
while(<FH>){
$file .= $_ }
close FH;
print "$file\n";


$cipher = $rc5->encrypt($file);

$rc5d = new Crypt::RC5($key, '12' );

$plain = $rc5d->decrypt($cipher);

print "$plain\n";

[download]

or 

#!/usr/bin/perl
use Crypt::Rijndael;

$key = chr(0) x 32; #key is all nulls here 
substr($key, 0, 1) = chr(1); #put 1 chr(1)in key just for fun 

print "key->$key\n";

$plaintext= "adrqwqqqqqqqqqqqqqqqqqqqqqqwrxcq4gfq3g2q45g2q43g5";
print "plaintext->$plaintext\n";
$plaintext16= get16($plaintext);
print "plaintext16->$plaintext16\n";


$cbc = new Crypt::Rijndael $key, Crypt::Rijndael::MODE_CBC;
$crypted = $cbc->encrypt($plaintext16);
print 'crypted->',"$crypted\n"; #keep encrypted string in different pr
+int string 
                                #to avoid character corruption of prec
+eding string 

$cbc = new Crypt::Rijndael $key, Crypt::Rijndael::MODE_CBC;
$decrypted = $cbc->decrypt($crypted);
print "decrypted->$decrypted\n";

#this sub makes all data blocksize of 16 bytes. 
sub get16 {
    my $data = shift;
    print "data=$data\n";
      return "\0" x ( 16 - length($data)%16 ) . $data;
      }

exit;

[download]

In reply to Re: Encryption/Decryption by zentara
in thread Encryption/Decryption by Anonymous Monk

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