The invention relates to a user interface-equipped computing device comprising means for implementing a series of applications, said means including two execution spaces. According to the invention, the applications of the second execution space (100, P1, 200, P2) have a level of security specifically higher than that of the applications of the first execution space (100, P1, 200, P2), said two execution spaces being hosted by a physical processing means which is designed such that it cannot be separated into two parts without destroying the physical processing means.