# [Q] How does unlocking a phone by IMEI work nowadays?



## zeroize (Jan 27, 2011)

There use to be free unlocking calculators for the old phone models. But it seems that it's impossible to unlock a modern phone for free. What I don't understand is how it works nowadays. You have to send the IMEI to a reseller, then wait for days (1 to 5) to get your code back.

I thought that smart hackers were profiting from their own unlocking calculators, created by themselves, but it seems that the delay getting the code is because some databases have to be accessed. And depending of the company that locked the phone that could be harder and more expensive to do.

So, how does it really work? Who are the original sellers and unlocking code creators?

Thanks!


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## saw01 (Jan 29, 2011)

Wish I could help.I'm also having to wait for my unlock code tio be sent.all I did was call up t mobile and asked about unlocking.have them the imei.they sent it to samsung and now I'm waiting for the code for my vibrant.it was all free.

Sent from my SGH-T959 using XDA App


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## zeroize (Jan 29, 2011)

saw01 said:


> Wish I could help.I'm also having to wait for my unlock code tio be sent.all I did was call up t mobile and asked about unlocking.have them the imei.they sent it to samsung and now I'm waiting for the code for my vibrant.it was all free.
> 
> Sent from my SGH-T959 using XDA App

Click to collapse



What do you mean "they sent it to Samsumg"? Is there a way to cheat companies to unlock their own phones?


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## the.rider1290 (Feb 2, 2011)

Phones are simlocked to inibith usage of other sim cards different from the one of the operator that gave you the phone: on this we all agree BUT in all the countries it's possible to unlock the mobile after a definied time, in italy for example is 9 months under payment and 18 months for free after purchase just going to your operator: many people don't know this really simple mechanism.

Here is the function of giving them your IMEI code: the algoritmh, specific for every operator, use your IMEI to calculate a number that must be the same that is written inside your phone: that's why they ask for IMEI and OPERATOR


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## zeroize (Feb 2, 2011)

the.rider1290 said:


> Phones are simlocked to inibith usage of other sim cards different from the one of the operator that gave you the phone: on this we all agree BUT in all the countries it's possible to unlock the mobile after a definied time, in italy for example is 9 months under payment and 18 months for free after purchase just going to your operator: many people don't know this really simple mechanism.
> 
> Here is the function of giving them your IMEI code: the algoritmh, specific for every operator, use your IMEI to calculate a number that must be the same that is written inside your phone: that's why they ask for IMEI and OPERATOR

Click to collapse



But is the algorithm really known or do unlockers get the unlock codes using insiders that work for the operator company? So this workers would illegally pick code by code from some database since they have to have the unlock codes in order give them for free after X months anyway.


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## the.rider1290 (Feb 2, 2011)

Think they just use software generators.... nowadays also Windows versions and software that costs millions went leaked...


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## thefuryx (Aug 30, 2011)

the.rider1290 said:


> Phones are simlocked to inibith usage of other sim cards different from the one of the operator that gave you the phone: on this we all agree BUT in all the countries it's possible to unlock the mobile after a definied time, in italy for example is 9 months under payment and 18 months for free after purchase just going to your operator: many people don't know this really simple mechanism.
> 
> Here is the function of giving them your IMEI code: the algoritmh, specific for every operator, use your IMEI to calculate a number that must be the same that is written inside your phone: that's why they ask for IMEI and OPERATOR

Click to collapse




but basicly if someone would manage to flash his IMEI with other from completely different phone he no longer uses would it do the job?


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## Fizdude (Aug 30, 2011)

I had the same problem with my old Samsung Jet, they wanted me to send it to them over a 30 day period costing me £25!


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## malayalapenkutti (Oct 15, 2011)

If you get the paid unlock code means the code provider get the Code from the particular Network Data base,...so it's Legal one...Then in free code generator the calculators generate the code,but the code generate by the program so it generate default codes.....I got the code for Unlocking the Phone from Network lock quickly and free of cost,i got the correct free Unlock code for my Nokia,Samsung Phones at here www.unlock-free.com and Unlock it........


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## shmootz (Oct 15, 2011)

I believe the reason that calculators are no longer possible is due to the fact that the manufacturer/provide uses random algorithms to generate the unlock codes, and are not based on the IMEI. That is, the unlock code can only be found in their database as they did not use the IMEI as part of the algorithm to generate the code in the first place; hence there is no way to reverse engineer them for newer/more common devices.


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## Theonew (Oct 15, 2011)

shmootz said:


> I believe the reason that calculators are no longer possible is due to the fact that the manufacturer/provide uses random algorithms to generate the unlock codes, and are not based on the IMEI. That is, the unlock code can only be found in their database as they did not use the IMEI as part of the algorithm to generate the code in the first place; hence there is no way to reverse engineer them for newer/more common devices.

Click to collapse



False. If this was true, then any hacker... anyone could do this. All unlock codes are based on your IMEI and phone model (carrier,country,etc).


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## hkimsiv (Oct 22, 2012)

Any one please help me. I have Asus Garminfone A50 locked by T-Mobile now I would like to unlock to use any sim card. IMEI:357355039003527 please help me or send unlock code to my e-mail[email protected]

Thank you


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## AirCombat (Oct 22, 2012)

hkimsiv said:


> Any one please help me. I have Asus Garminfone A50 locked by T-Mobile now I would like to unlock to use any sim card. IMEI:357355039003527 please help me or send unlock code to my e-mail[email protected]
> 
> Thank you

Click to collapse



Believe me, it's not as easy at it seems to get SIM unlock codes. Your best bet is to find either a trustworthy site online, or call your provider and tell them you're travelling internationally and you need to change SIM cards... they may charge you but it only needs to be done once. However, if you have patience eventually someone will write an app to do it for free. But that could take months, even years. I'm currently trying to figure out a way to unlock mine without doing either of the methods outlined above and I've spent days researching this and I still am not much closer...

-AC


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## handasan10 (May 22, 2013)

Try here: http://forum.gsmhosting.com/vbb/f88/


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## joe654 (Aug 21, 2013)

well this is my understanding  the unlock code database will be having 2 primary keys 1 will be the IMEI number and another one is the key which will be used for generating the unlock code which is unknown to the outside world. 

so when some one request for the unlock code the service provider, (either the phone company or thirdparty) have to refer thru this 2nd key for generating the key but since the key generation is done from the manufacture end the database is acting like a blackbox.

-cheers


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## 4ne fixer (Jan 25, 2014)

just get your imei off the web to save you from millions of copies that are likely coming up


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## tewilove (Jan 26, 2014)

hello, some time before I digged into SONY unlock, my conclusion is that it's impossible to brute force or you really need an insider in that company.
// STEP:
//  t = NCK + SALT
//  h = sha256(t)
//  9.times { h = sha256(h) }
//  assert(h == HASH)
// IMEI: 353588050129**7
// NCK : 647765421762**43
SALT and HASH are programmed in trim area, and don't know how to calculate those two, only way is to get the phone and extract them.


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## 1sagain (May 6, 2015)

I always thought that codes were pre calculated when phones are manufacturered.

I know for some phones the ROOT AWAY app (on samsungs) takes off the sim lock.


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## iamdude (Oct 26, 2015)

@tewilove, your finding is sony-specific or docomo-specific? As you know the same Sony models is sold in Japan by a different operators - Docomo, Softbank and KDDI. But always with a sim lock.

With root we could read the whole TA, so we could calculate unlocking code? What do you think?


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## cinnaC2C (Jan 29, 2016)

shmootz said:


> I believe the reason that calculators are no longer possible is due to the fact that the manufacturer/provide uses random algorithms to generate the unlock codes, and are not based on the IMEI. That is, the unlock code can only be found in their database as they did not use the IMEI as part of the algorithm to generate the code in the first place; hence there is no way to reverse engineer them for newer/more common devices.

Click to collapse



If they don't use the IMEI, then why do the unlockers ask for it? There should be no need for it if that was the case, unless, it's just to verify your phone model or something?


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## zeroize (Jan 27, 2011)

There use to be free unlocking calculators for the old phone models. But it seems that it's impossible to unlock a modern phone for free. What I don't understand is how it works nowadays. You have to send the IMEI to a reseller, then wait for days (1 to 5) to get your code back.

I thought that smart hackers were profiting from their own unlocking calculators, created by themselves, but it seems that the delay getting the code is because some databases have to be accessed. And depending of the company that locked the phone that could be harder and more expensive to do.

So, how does it really work? Who are the original sellers and unlocking code creators?

Thanks!


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## kurvnet (Jul 15, 2016)

From what I know unlocking is basically and algorithm that requires three parameters:
- IMEI number
- Phone model
- Network locked to

In some instances the Phone model and Network can be retrieved based on the IMEI so the IMEI is the most important that is required. With IMEI the algorithm simulated the phone and checks different things. It then tries to match the IMEI and generate the code. The reason it takes 2-5days is because the algorithm just needs that much time to run. Some time it matches the data quickly and you get the information straight away, other times it is still checking.

The Manufacturers/network providers usually have a database where the just look up for your IMEI number can send you the code.  You obviously have to be the customer and meet certain criterion.

Hope this help...


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## !%d (Sep 10, 2016)

Theonew said:


> False. If this was true, then any hacker... anyone could do this. All unlock codes are based on your IMEI and phone model (carrier,country,etc).

Click to collapse



i think what was meant was that when the phone is manufactured, it is assigned a random unlock_code, and then the [IMEI, unlock_code] is stored in a database (if i were an unscrupulous manufacturer/service-provider, this would be one of my go-to methods for disenfranchising consumers via vendor lock-in (if i was a scrupulous company, i would forgo any mechanisms that unfairly limit the freedom of the consumer, but this is another topic of corporate policy/ethics)), this way it is completely reverse-engineer -proof. a hacker could still be able to access this, but would have to go the route of breaking into their servers (which may be possible if the company does not implement good security policies)


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## kentek (May 11, 2017)

*imei unlock database*

The code is randomly generated by the manufacture for each network and a copy of the database is sent to the network provider.
Unlock company's pay to have access to the database on a per check basis this is the reason for the delay in response


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