| The simplest and easiest way to unlock mobile is to | | | | and the verification number is stored in an in-built |
| put the unlock code there and unlock it. Usually the | | | | database of the phone. The second method is |
| mobile is locked with the SIM, that is, the SIM | | | | verification through obscure mathematical formula. In |
| installed has restricted usage. This is a normal | | | | this method, the code provided undergoes a |
| situation that a locked mobile phone will always ask | | | | mathematical calculation following an obscure method |
| for its' unlock code. It appears on the screen of the | | | | provided by the provider. |
| mobile. | | | | Available Security Measures |
| Procedure | | | | Previously there was the possibility to crack the |
| Depending on the manufacturer types, the lock is | | | | algorithm generated using reverse engineering |
| available in different format, hence is the unlocking | | | | process. These unlocking methodologies were |
| procedure. For example, if we use mobile phone like | | | | available even without any cost involved at the |
| T610 from Sony Ericsson, we may receive a warning | | | | customer's ends. However, current robust and |
| message saying, "Insert correct SIM card", in the | | | | complex algorithm leaves a minimum possibility to do |
| case of wrong SIM card. However, once the proper | | | | the same thing, which also ensures its non-availability |
| unlocking code is entered, the display message will be | | | | using any free mode of operation. |
| turned into "Network Unlocked". On the other hand, | | | | A more cautious effort is made when providers use |
| mobile phones manufactured by AT&T explain that | | | | a random number that can only be retained by the |
| status of the mobile phone if it is locked. | | | | provider who applied the lock. However, this method |
| Verification of Code | | | | is not always flawless as it can be cracked by using |
| The code is essential for removing all SIM locks from | | | | special test equipments. |
| a particular mobile phone. It is known as master code. | | | | In most of the cases, the phone are made secure by |
| Sometimes it is also referred to as network code | | | | using built-in software which restricts to enter the |
| key. | | | | unlock code for many times, commonly not more |
| There are primarily two methods for verifying the | | | | than 4 times. After that, the phone gets hard-locked |
| unlock code once inserted by the user. One is | | | | which needs a special equipment provided by the |
| verification through directly accessing database. In | | | | provider itself to unlock it once again. |
| this method, the phone itself verifies the unlock code | | | | |