A computing device configured to compute a data function on a function-input value, the device comprising an electronic storage storing a first table network configured for the data function, - the computing device comprising an electronic processor coupled to the storage and configured to obtain multiple first table inputs for the first table network, the multiple first table inputs including the function-input value, and to compute the data function by applying the first table network to the multiple first table inputs to produce multiple first table outputs, the multiple first table outputs including a function-output value, the function-output value corresponding to the result of applying the data function to the function-input value, wherein - the electronic storage is further storing a second table network configured to cooperate with the first table network for countering modifications made to the first table network, the electronic processor being configured to obtain multiple second table inputs for the second table network, the second table inputs including the multiple first table outputs and the second table inputs sharing at least one input with the multiple first table inputs, and to apply the second table network to the multiple second table inputs, the second table network being configured to verify for at least a specific one of the multiple first table outputs if an unmodified first table network could obtain the specific one of the multiple first table outputs from the given at least one of the multiple first table inputs, - the second table network produces second table outputs including a protected function output, the protected function output being equal to the function output in case the verification is successful and the protected function output being unequal to the function output in case the verification is unsuccessful for at least some values of the multiple first table inputs. - the computing device comprising an electronic processor coupled to the storage and configured to obtain multiple first table inputs for the first table network, the multiple first table inputs including the function-input value, and to compute the data function by applying the first table network to the multiple first table inputs to produce multiple first table outputs, the multiple first table outputs including a function-output value, the function-output value corresponding to the result of applying the data function to the function-input value, wherein - the electronic storage is further storing a second table network configured to cooperate with the first table network for countering modifications made to the first table network, the electronic processor being configured to obtain multiple second table inputs for the second table network, the second table inputs including the multiple first table outputs and the second table inputs sharing at least one input with the multiple first table inputs, and to apply the second table network to the multiple second table inputs, the second table network being configured to verify for at least a specific one of the multiple first table outputs if an unmodified first table network could obtain the specific one of the multiple first table outputs from the given at least one of the multiple first table inputs, - the second table network produces second table outputs including a protected function output, the protected function output being equal to the function output in case the verification is successful and the protected function output being unequal to the function output in case the verification is unsuccessful for at least some values of the multiple first table inputs.