Mobile phone SIM cards, Cloning and related devices sold on eBay...

At one time cloning a mobile phone SIM card was an easy process; in order to create a clone 2 pieces of information needs to be known about the SIM card you are wanting to clone:

1. IMSI - this is the number - normally written on the SIM card

2. Ki - this is a hidden number which can only be discovered electronically.

Before cloning became a more common practice it was possible to discover the Ki number through a cracking program. This would allow a user with a PC and suitable hardware (card reader) to try every combination one by one through a software application until the code was discovered.

Now there is a problem with this. UK phone networks are now only issuing SIM cards that have an anti-tamper device built into their software. If an application such as the above attempts to discover the Ki number through multiple sequential attempts the SIM locks to a state where it is unusable. This not only renders the SIM card useless but also prevents any software system presently commercially available from discovering the Ki number.

If a user tries to use a cracking application it will render the SIM useless - it will no longer register to any network. I believe the maximum number of Ki number read attempts tollerated by a contemporary SIM card is just 8 out of several hundred thousand possible combinations. The chances therefore of discovering the Ki number and thus being able to clone your SIM card are very, very low - I suspect you are more likely to win the lottery.

Older SIM cards - pre 2001 may still be possible to clone, the UK networks are generally ahead of the SIM cloning game, and the suitability of SIM card cloning or backup applications and hardware / adapters is probably now limited to less developed regions of the world where SIM cloning has not presented a significant problem to the network operators.

Important Update: I have received an email from an eBay member asking if this information is still current. As of October 2007, there are no reports of any application capable of cracking the latest SIM card Ki number that I can find. Many thanks to all those who have emailed to say the guide was of use. I hope this is of continuing help, please read on...

I hope this advice proves useful to anyone planning to buy a SIM card reader / writer with a view to cloning. Such devices are known as:

Silver cards

Green cards

Platinum cards

16 in 1

12 in 1

10 in 1

8 to 1

Super SIM

etc, etc.