Gevey Sim iPhone 4 Baseband Unlock For Indian Users – It Works But Its Duplicate Gevey Sim Every Where

Today I went to different markets in delhi with one of my friend Sumit Gupta who had a iphone 4 locked with AT&T he got from US via some friend traveling from US to India. His iphone 4 was running ios firmware 4.1 with baseband 2.10 after searching a lot, and waiting for couple of months he decided to try gevey sim solution which is actually a small chip gets into iphone 4 with your existing sim card and does the magic and unlock your iphone with baseband Baseband 2.10, 3.10.1, 4.10, 4.10.1 firmwares iOS 4.0, 4.1, 4.2.1, 4.3 , 4.3.1 and 4.3.2


For all those wondering what is Gevey Sim all about, It is a small chip which lets you unlock iPhone 4 01.59.00, 02.10.04 & 03.10.01 baseband. Unlike Ultrasn0w unlock, Gevey SIM hack is not a software but a SIM interposer which sits electrically between the SIM card and baseband hardware to perform a classical middle man attack and in order to keep your iphone in unlocked state you will always need to keep the chip inserted into your iphone with your SIM card, just in case if your iphone is out of power to due to low battery or some other reason then you will need to unlock your phone again using the gevey sim unlock procedure.


How Does Gevey Sim Works ?

Please Note: It basically works by forcing the activation of the baseband by dialing the emergency number, and this vulnerability up to iOS 4.3 firmware.

So to further detail this, SIM card holds many different types of information, but the part most involved with carrier lock is the IMSI number, which is a unique code that corresponds to your account in the mobile carrier’s database.

A sample IMSI might look like this

310 150 987654321

The first two segments are known as Mobile Country Code (MCC) and Mobile Network Code (MNC) respectively, and in the example above the IMSI indicate the SIM is from USA (310) AT&T (150).

When the iPhone baseband is loaded into memory, it checks the MCC and MNC against its own network lock state stored in the seczone. If the combination is allowed, the cell radio is activated and vice versa.

The earliest iPhone baseband revisions only check IMSI twice following a restart, therefore it is very easy to spoof information in order to bypass the check. Nevertheless, the baseband was soon updated to validate SIM more aggressively and the method no longer works.

Apple made the authentication procedure mode difficult to crack by introducing a 4-byte TMSI (Temporary Mobile Subscriber Identity) which now identify each handset before IMSI is sent and processed.

Now Gevey Sim manages to get a TMSI by dialing a emergency number When the network issues TMSI for your connection, Gevey’s SIM interposer finds an acceptable MCC/MNC combination by rapidly cycling a list of IMSI. To prevent your baseband from detecting the fake IMSI, toggling the flight mode for a second is enough. This spoofing of IMSI and ICCID makes your carrier think that your iPhone 4 is factory unlocked.

The above method of spoofing your IMSI and ICCID is actually not legal, as if your phone provider notices and plans to take some action then they might might request your IMEI and ban your sim card from network and stop it from receiving signals.

Things You Should Know About Gevey Sim Sold In India

1. All most all the shops in delhi, including the popular gaffar market area every one is selling a duplicate gevey sim which works but might give you heating issues and fast battery drainage issue.

2. It works if your network handles 112 calls properly according to the GSM standard. So before buying Gevey SIM, first step is to dial 112 from your phone and check the response.

3. If your network validates your IMSI on every incoming call, do not think of buying Gevey SIM.

4. Even if your network do not validates your IMSI on every incoming call, you still have to revalidate your IMSI if your iPhone loses power, loses the reception or move to another PLMN. In all of these cases, your TMSI expires and has to be obtained again.

5. Not all 3G network will work, for example you will not see T-mobile with 3G service on the iPhone but you will see it working with edge.

6. SIM interposer will not harm your iPhone hardware but it can get your account banned from your network provider if they knew that you have spoofed your IMSI and ICCID. Its only in China that GSM companies know this loophole but still don’t bother to close it.

In order to find out whether your Gevey Sim is original or not, refer these two guides here and here

Step By Step Instructions To Unlock Your iPhone With Gevey Sim

1. Switch off your iphone 4 and insert the Gevey Sim as shown in the image above in your locked iPhone 4.

2. Turn on your Iphone 4 . It will show “No Sim Card Installed” message . Just accept and goto next step.

3. Wait for 15 seconds and Dial 112 . As you connect with the call , disconnect it after 2 seconds . Please Note that 112 is an emergency

number .

4. Now goto Settings and select Airplane Mode On. Again turn it Off.

5. You will now see a “Sim Failure” message. Wait for few seconds for the network bar to appear .

6. Repeat steps 3 to 4 if it doesn’t show the network signal bars in your first try.

Some Images I Took Before Unlocking iPhone 4 With Gevey Sim

IMG_2653 IMG_2654 IMG_2655 IMG_2656 IMG_2657 IMG_2658

Demo Video Gevey Sim In Action Below

Short Video I Recorded While Gaffar Market Dealer Was Doing The Unlock [Delhi, India]

Points To Note For Airtel & Vodafone: Some insights I got from a delhi gaffar market dealer, selling gevey sim solution that, if you unlock your iphone and use givey sim on airtel, if your 3g is on and you are not getting signals than you might need to repeat the gevey sim procedure to unlock your phone and for vodafone users you may be able to use 3g or even edge network on your phone if you are using gevey sim.
[ Sources – Singularity ]


  1. Ankit says

    Hi, first Good post. I’m an iPhone fan too. I’m going to US (San Jose, CA) next week. Is it possible to buy an iPhone which I can use in India (Vodafone, Delhi) given that Apple only sells iPhone with AT&T/Verizon in US.

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