Is It Possible to Clone the SIM Card of Your GSM Phone?

I have a Blackberry 8700 for work. It’s a great device with some fantastic features, but as a basic cell phone it’s awkward and bulky. When I’m not working, I’d prefer to carry around a basic flip phone but don’t want to pay for an extra phone line. Fortunately my cell provider uses GSM cell technology which means the phones on the network all use a Subscriber Identity Module (SIM) card (a little device that contains everything necessary for the phone to access and use my providers cell network). Using this cell technology allowed me to go to my provider, purchase a flip phone, and, depending what I needed for the day, simply swap the SIM card between the new flip phone and the Blackberry device. Not the most elegant solution, and repeatedly swapping the SIM does run the risk of damaging it. Unfortunately I have no other option for my situation — or do I? Why can’t I just copy my SIM card and leave one card in each device and only use them one at a time?

What you need to copy a SIM card

I might be simplifying things but you need two basic things from your original SIM card in order to copy (or clone) it:

1. IMSI (International Mobile Subscriber Identifier): The number normally written on the SIM card itself
2. Authentication key (Ki): A hidden number which can only be discovered electronically

Getting the IMSI number is fairly simple: Do a little web research to learn more about what this number looks and where its located, and then examine your card for such a number. Extracting the Ki from the SIM card is much more difficult because you would need a device capable of reading the card and some sophisticated software to decrypt the Ki. Search the web for this device and software and you’ll find several sites selling SIM card duplicators. Matter of fact, most of these items are extremely affordable. Sound to good to be true? It is.

Why SIM card duplication or cloning is nearly impossible

There was a time when SIM card security was less than ideal. Cloning cards was a real concern for cell providers and when money is at stake you can bet they took the necessary steps to address their security weaknesses.

Cell providers currently use SIM cards that have an anti-tamper device built into their software. If Ki cracking software attempts to discover the Ki number through brute force sequential numeric attempts, the SIM locks to a state where it is unusable. In short, you’re phone is useless and you need to go back to your provider and attempt to get a replacement SIM.

V1 SIM cards which I believe were made prior to 2001 are possible to duplicate. Unfortunately, anything younger than that (V2 of 3G SIM cards) contain the anti-tamper software and are almost impossible to clone. And it’s the SIM card version that is the “fine print” on those very tempting SIM card duplicators.

The “fine print” of SIM duplicators

SIM card duplicators are often listed for sale with one of the following titles:

• Silver cards
• Green cards
• Platinum cards
• 16 in 1
• 12 in 1
• 10 in 1
• 8 to 1
• Super SIM

All of these items look as if they will do the job of cloning a SIM card, they basically claim that is exactly what they will do. If, however, you read the description closely, you’ll notice that they claim to only work with V1 SIM cards. Those are the pre-2001 SIM cards that do not contain the anti-tamper software and therefore easy to clone. Take one of those duplicators and attempt to clone a V2 or 3G SIM and you’ll likely render your card useless. Buyer beware!

The possibility to clone does exist but not worth the effort

I honestly believe that someone could successfully clone a V2 or 3G SIM card. The process itself is illegal as far as I know, and if you were to simultaneously use the original and copied card (intentionally or by accident), you’re cell provider would undoubtedly know and most likely revoke your access to their cell network immediately. For the average cell customer, the possibility of cloning a newer version SIM card is next to impossible and simply not worth the effort. If, however, you actually know how to successfully clone a 3G SIM card, then by all means let me know.