A computing device comprising: a display device for presenting a user interface; a processor; and a storage device storing instructions executable by the processor to: for each of a threshold number of rounds: display a plurality of candidate regions on the user interface, each candidate region including a plurality of candidate authentication objects, receive input indicating a device access control response, and if the input includes selection of a first candidate region of the plurality of candidate regions, determine that the input is a successful input responsive to determining that the first candidate region includes one of a plurality of device access code objects included in a device access code used to control access to the computing device; and after performing the threshold number of rounds, selectively allow access to the computing device based on a number of rounds that included a successful input, wherein the threshold number of rounds, a number of candidate regions displayed in the user interface, and/or a number of candidate authentication objects displayed in each candidate region is dynamically adjusted based on a location of the computing device and/or data received from a sensor of the computing device. a display device for presenting a user interface; a processor; and a storage device storing instructions executable by the processor to: for each of a threshold number of rounds: display a plurality of candidate regions on the user interface, each candidate region including a plurality of candidate authentication objects, receive input indicating a device access control response, and if the input includes selection of a first candidate region of the plurality of candidate regions, determine that the input is a successful input responsive to determining that the first candidate region includes one of a plurality of device access code objects included in a device access code used to control access to the computing device; and after performing the threshold number of rounds, selectively allow access to the computing device based on a number of rounds that included a successful input, wherein the threshold number of rounds, a number of candidate regions displayed in the user interface, and/or a number of candidate authentication objects displayed in each candidate region is dynamically adjusted based on a location of the computing device and/or data received from a sensor of the computing device. for each of a threshold number of rounds: display a plurality of candidate regions on the user interface, each candidate region including a plurality of candidate authentication objects, receive input indicating a device access control response, and if the input includes selection of a first candidate region of the plurality of candidate regions, determine that the input is a successful input responsive to determining that the first candidate region includes one of a plurality of device access code objects included in a device access code used to control access to the computing device; and display a plurality of candidate regions on the user interface, each candidate region including a plurality of candidate authentication objects, receive input indicating a device access control response, and if the input includes selection of a first candidate region of the plurality of candidate regions, determine that the input is a successful input responsive to determining that the first candidate region includes one of a plurality of device access code objects included in a device access code used to control access to the computing device; and after performing the threshold number of rounds, selectively allow access to the computing device based on a number of rounds that included a successful input, wherein the threshold number of rounds, a number of candidate regions displayed in the user interface, and/or a number of candidate authentication objects displayed in each candidate region is dynamically adjusted based on a location of the computing device and/or data received from a sensor of the computing device.