Distributed IMEI Blacklisting

Small, portable and high value, mobile devices – and the information stored in them – are attractive to criminals. As high-end handsets can be worth hundreds of dollars,
there is a major international black market for mobile devices obtained through theft, fuelled in part by organized crime.

For the victim, the experience can be traumatic, as well as costly: they lose their handset, a highly personal item, and could get hurt during a robbery. In countries where device theft is rife, insurance companies will have to charge high premiums, while consumers may end up unwittingly buying stolen goods. The legal handset market and the taxes it generates are undermined. People that have had their devices stolen are particularly vulnerable to their personal data being used to commit a range of additional crimes.

The GSMA allocates Type Allocation Codes (TAC), which are combined with a serial
number allocated by the manufacturer to create International Mobile Equipment Identifiers (IMEIs).

With our trusted IMEI blacklist network operators, smartphone manufacturers and end users list and identify blacklisted phones from anywhere.

The IMEI system underpins the distributed blacklist service which stores the unique identifiers of mobile devices reported as lost or stolen by customers of mobile operators.

When mobile operators detect a device connecting to their network that is registered
on the Distributed Blacklist, the IMEI enables them to block its use. Once thieves learn that stolen devices are likely to be quickly disabled, device theft becomes much less attractive.

Governments, law enforcement agencies and mobile operators need to work together to deter handset theft. The Distributed IMEI Blacklisting makes it easy for mobile operators to exchange stolen handset data with law enforcement and other operators.

The Distributed IMEI Blacklisting facilitates a coherent approach to cross-border information sharing, increasing the effectiveness of national measures. Note, however, regulation needs to allow stolen device information to be shared across all countries.

With the Distributed IMEI Blacklist mobile operators will be able to ensure that customers can have their smartphones blocked faster, regardless of the number of contracted service providers and phone numbers. The goal is to build a decentralized blacklist that allows providers worldwide to view the blocked IMEI numbers.

At the moment, the information about blacklisted devices is used only within processes on the network-side. Opening of access to this information could provide basis for new, complimentary solutions and mechanisms build e.g. on the device-side (blocking of connectivity directly on the device, deletion of sensitive data, reporting device location to enable tracking, etc.).

In the same manner, the maintenance of the information stored on blacklist is today done solely by the operators. The blockchain based solution – given that corresponding permissions would be granted – could allow direct integration for example others for Asset Management systems. Such integration would provide aims e.g. to corporate customers to directly manage information about devices used by their employees (or any mobile or IoT device being owned by such company) on their own.

Additionally, further services or products could be build. It would be a first step towards an ecosystem of participants and services that could be build around this solution and where full potential can be achieved only thanks to enablers like blockchain.

Part of our Antifraud Namespace is the capability to add/remove numbers to distributed IMEI Blacklists. Ideally such blacklists are shared across carriers.


With the function https://coin.codeb.io/antifraud.asmx?op=BlacklistIMEINumber you can add any number to the IMEI Blacklist whereby SSIAddress is the Self-Sovereign Identity hosting the blacklist and ChainAddress and Password are required to digitally sign the addition to the blacklist.

Please note that the administrator of SSIAddress has to grant you the permission to add numbers to the blacklist.


You can use the function https://coin.codeb.io/antifraud.asmx?op=RemoveIMEINumberFromBlacklist to remove a previously added number from the list.


The most important part is to check if a number is blacklisted. To do so you query the blacklist of the SSI for the number with the function https://coin.codeb.io/antifraud.asmx?op=CheckIMEIBlacklisted

This function returns a long value indicating how many entities detected and blacklisted a number.


Above we explain the syntax of our web services APIs. Kindly note that we offer broad range of APIs such as websockets, RESTful APIs and of course traditional DNS AntiSPAM interfaces. Just contact us and explain how you would like to connect!