I only had one key & needed a spare just in case, this is what I did (just so people know if you lose a HISS key & don't have a spare the only fix is buy complete ECU, key & barrel from Honda unless you kept the silver tag that came with new bike which has a serial number. That is only a number so Honda can do a replacement key with if all original keys lost & that key has to come from factory.
I can't take credit for this procedure as it was found doing search & asking questions, but the info came from other models with HISS & couldn't find anything VFR specific so I'm writing this because it was done on my 04 VFR800 without a problem. My local Honda dealer charges $50AU to program a key & $58AU for a blank key so that is $108 total, It cost me all up $25.45.
1. Buy a blank HISS key, these are different from a normal key only due to chip that is located in plastic part but they look the same as a none HISS key, I found them on eBay for $25USD delivered (there normally over $50 here in Australia)
2. Take your new key blank with your existing key & have it cut to work (before you bother to program make sure the new key when cut works in all locks because there are a limited number of keys your allowed to program per bike)
3. Go to an electronics store & buy a 1W 100R Carbon Film 5% Resistor, now this is where I went ghetto because you can bother to make the special Honda lead which if your able to buy costs over $100 buying clips & plugs & do soldering but I couldn't be bothered because I was only going to use this lead once so I had electronic jumper leads which are simply the alligator clips each end of a wire & you want the small alligator clip type due to needing to get inside a bike plug with limited space. The good thing about buying these leads is you can place them in your tool kit & use them for other things when needed.
4. The VFR800 plug used is the Ignition Pulse Generator (red plug RHS bike located same place the fuel injection large grey plugs are positioned), this plug has only two wires, the solid yellow is your positive + & the other duel colour is your negative - feed.
5. Unplug the red plug & the male part of plug that feeds back to the ECU is what you need to connect to, so using you small alligator clips so you can get to the terminals and plug clip them on making sure you don't have them touching each other (the small test alligator leads have plastic covers to shield them or you can just strip some of the plastic shielding off the wire if you want after the plug if you can't get what you have into the red plug).
6. The Yellow wire from the red plug you use on the other end of the alligator lead & clip on your 1W 100R resistor & then get another lead & connect to other side of resistor (remember I did say ghetto lead) that leaves you with an alligator clip to connect to your battery positive terminal +
7. The other wire you connect to the negative terminal on the battery -
8. Turn the ignition key to ON using your original key. The immobilizer indicator (HISS) light should come on and stay on (if it starts flashing after 10 seconds there is a fault in your system).
9. Now disconnect the positive + battery connector for 5 seconds before reattaching it to the battery terminal. The indicator should now come on for 2 seconds then begin to flash repeatedly four times. This indicates the system is now in registration mode. At this point all previous keys except the one in the ignition have cleared or cancelled from the ECU memory, so if you have any extra spares they will need to be re-registered.
10. Turn the ignition to OFF and remove the original HISS key, put it a couple of meters away from the bike so it doesn't interfere with the transponder in the new key.
11. Insert the new key and the ignition to ON. The immobiliser indicator light should come on for 4 seconds then begin to flash repeatedly four times. This indicates the system has registered the new key. Success!
12. If you have any extra keys you want to register, repeat step 10-11. Don't put the original key you started the process with in as it’s already registered.
13. Once you have registered your spare keys, turn the ignition to OFF, remove the ghetto lead and reconnect your red plug sensor.
14. Now check all your keys start your bike.
NOTE: make sure with the ghetto lead you don't short out any connection to the bike frame, if your clumsy wrap it all in electrical tape & if your fussy make a lead with solder connections & shrink sleeve.