Browse Definitions:

locked down device (LDD)

A locked down device (LDD) is a mobile device, typically a smartphone, that is shipped by a vendor with the ability to accept only the SIM card that originally came with it.

Vendors lock down devices before shipment to maximize their profit by making it difficult for users to switch carriers. For example, AT&T might lock a smartphone so that a user cannot easily switch to Verizon (or vice-versa). When corporations issue mobile devices to their employees in the corporate owned personally enabled (COPE) model, locking down each device can help to control support and management costs by discouraging unauthorized device exchanges among employees.

Some people try to unlock their smartphones so that they can accept SIM cards other than the original. Proponents of the practice argue that consumers should be free to change carriers when a subscription contract expires without having to discard hardware that they purchased outright. Nevertheless, smartphone unlocking was declared illegal in the United States in January 2013, overturning an earlier decision by the Copyright Office. The law applies to all devices purchased on or after October 28, 2012.

Device unlocking differs from jailbreaking, which involves removing certain manufacturer or carrier restrictions from a device, such as running a privilege escalation attack to alter the manufacturer's OS (operating system) by installing a custom kernel.

This was last updated in June 2013

Start the conversation

Send me notifications when other members comment.

By submitting you agree to receive email from TechTarget and its partners. If you reside outside of the United States, you consent to having your personal data transferred to and processed in the United States. Privacy

Please create a username to comment.


File Extensions and File Formats

Powered by:


  • risk map (risk heat map)

    A risk map, also known as a risk heat map, is a data visualization tool for communicating specific risks an organization faces. A...

  • internal audit (IA)

    An internal audit (IA) is an organizational initiative to monitor and analyze its own business operations in order to determine ...

  • pure risk (absolute risk)

    Pure risk, also called absolute risk, is a category of threat that is beyond human control and has only one possible outcome if ...


  • cloud ecosystem

    A cloud ecosystem is a complex system of interdependent components that all work together to enable cloud services.

  • cloud services

    Cloud services is an umbrella term that may refer to a variety of resources provided over the internet, or to professional ...

  • uncloud (de-cloud)

    The term uncloud describes the action or process of removing applications and data from a cloud computing platform.


  • federated identity management (FIM)

    Federated identity management (FIM) is an arrangement that can be made among multiple enterprises to let subscribers use the same...

  • cross-site scripting (XSS)

    Cross-site scripting (XSS) is a type of injection security attack in which an attacker injects data, such as a malicious script, ...

  • firewall

    In computing, a firewall is software or firmware that enforces a set of rules about what data packets will be allowed to enter or...




  • bad block

    A bad block is an area of storage media that is no longer reliable for storing and retrieving data because it has been physically...

  • all-flash array (AFA)

    An all-flash array (AFA), also known as a solid-state storage disk system, is an external storage array that uses only flash ...

  • volume manager

    A volume manager is software within an operating system (OS) that controls capacity allocation for storage arrays.


  • hybrid hard disk drive (HDD)

    A hybrid hard disk drive is an electromechanical spinning hard disk that contains some amount of NAND Flash memory.