Transition between masked representations of a value during cryptographic calculations

In a method for the transition from a first masked representation of a value to be kept secret to a second masked representation of the value, according to a first aspect of the invention at least one previously calculated table with a plurality of entries is used, and the calculation is carried out depending on at least one veiling parameter, in order to prevent the value to be kept secret from being spied out. According to a second aspect of the invention, at least one comparison table is used, which, for each table index, provides the result of a comparison between a value dependent on the table index and a value dependent on at least one masking value. A computer program product and a device have corresponding features. The invention provides a technique for protecting the transition between masked representations of a value from being spied out, wherein the masked representations are based on different masking rules.