If you insist on using a regex: 
#!/usr/bin/perl -w
use strict;
while(<DATA>){
    if(/\s+encryption key (\d+) size (\d+)bit \d+ (\S+)/){
        print qq|$1\t$2\t$3\n|;
    }
}

1;

__DATA__
show run
  Building configuration...

  !
  encryption key 1 size 40bit 7 621AA6093A25 transmit-key
  encryption key 2 size 40bit 7 7260637E4720
  encryption key 3 size 40bit 7 0F733F116035
  encryption key 4 size 40bit 7 03B71F3D601D
  encryption mode wep mandatory
  !

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In reply to Re: Extracting specific text info from the config file ouput by InfiniteSilence
in thread Extracting specific text info from the config file ouput by ramya2005

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