An electronic cryptographic device arranged to perform a cryptographic operation on input data obtaining output data, the cryptographic device comprising - an input interface arranged to receive the input data, - a memory arranged to store an internal state, the internal state comprising one or more data elements (311, 312, 313), the internal state being represented in the memory as one or more sets of shares (321, 322, 323), a set of shares in the memory having a corresponding set of Fourier coefficients (331, 332, 333) according to a discrete Fourier transform in a finite field, a proper subset of the Fourier coefficients corresponding to a set of shares determining one or more data elements of the internal state, - a processor circuit configured to - perform the cryptographic operation by repeatedly updating the internal state, an initial internal state being derived from the input data, the output data being derived from a final internal state, an updated internal state being formed by updating the one or more sets of shares representing the internal state, a proper subset of the updated Fourier coefficients corresponding to an updated set of shares determining the one or more updated data elements of the updated internal state, - apply an output operator to the final internal state to derive the output data, the output operator mapping the one or more sets of shares to the data elements of the output data. - an input interface arranged to receive the input data, - a memory arranged to store an internal state, the internal state comprising one or more data elements (311, 312, 313), the internal state being represented in the memory as one or more sets of shares (321, 322, 323), a set of shares in the memory having a corresponding set of Fourier coefficients (331, 332, 333) according to a discrete Fourier transform in a finite field, a proper subset of the Fourier coefficients corresponding to a set of shares determining one or more data elements of the internal state, - a processor circuit configured to - perform the cryptographic operation by repeatedly updating the internal state, an initial internal state being derived from the input data, the output data being derived from a final internal state, an updated internal state being formed by updating the one or more sets of shares representing the internal state, a proper subset of the updated Fourier coefficients corresponding to an updated set of shares determining the one or more updated data elements of the updated internal state, - apply an output operator to the final internal state to derive the output data, the output operator mapping the one or more sets of shares to the data elements of the output data. - perform the cryptographic operation by repeatedly updating the internal state, an initial internal state being derived from the input data, the output data being derived from a final internal state, an updated internal state being formed by updating the one or more sets of shares representing the internal state, a proper subset of the updated Fourier coefficients corresponding to an updated set of shares determining the one or more updated data elements of the updated internal state, - apply an output operator to the final internal state to derive the output data, the output operator mapping the one or more sets of shares to the data elements of the output data.