A way for securely protecting secret information—for example, a secret key—in a programmed electronic device is provided. A technique is disclosed for protecting secret information in a programmed electronic device that includes a non-trusted memory containing software, a data memory containing the secret information, and an access restriction logic unit that is adapted to allow or block access to the secret information wherein the secret information is adapted to be used for verifying the integrity of the software. In one embodiment, when starting up the programmed electronic device, the access restriction logic unit allows access to the secret information. Then the secret information is accessed for use in verifying the integrity of the software, and subsequently the access restriction logic unit blocks further access to the secret information. Embodiments of a semiconductor device and a programmed electronic device comprising similar features are also disclosed.