A conventional method of verifying alteration of an image file has a problem of security and may negatively affect user convenience. An image processing apparatus according to the present invention records, as an image file, input image data and a plurality of types of parameters input by the user, and stores, for each of parameter types classified in accordance with the features of the parameters, first security information based on the plurality of types of parameters. When reading out the image file, second security information is decided for each of parameter types based on the plurality of types of parameters included in the image file. If determined that the pieces of security information for any of the parameter types do not coincide, processing for the image file is changed in accordance with information to be used to restrict the processing to be executed for the image file.