The invention relates to a method for verifying a memory block of a nonvolatile memory, wherein, at a first point in time, a first authentication code for the memory block (131, 132, 33) is determined (209) by using a secret keyword and is stored (211) in an authentication code memory table (120), at a second point in time, for the purpose of verification, a second authentication code for the memory block (131, 132, 133) is determined (307) by using the secret keyword and is compared (307) to the first authentication code, and the memory block (131, 132, 133) is verified (309) if the first authentication code and the second authentication code agree.