The invention relates to a data-processing method that includes encoding a plurality of data of n bits into code words having a predefined constant Hamming weight, characterized in that said method also includes using (4000) encryption operations or arithmetic operations on the resulting code word(s) and also in that encoding each datum includes: decomposing (100) the datum into a plurality of m bit sequences to be encoded, m strictly being less than n; encoding (300) each bit sequence into a partial code word, each having a predefined Hamming weight, such that the sum of the Hamming weights of the partial code words are equal to the Hamming weights of the code word; and concatenating (300) the partial code words such as to produce the code word corresponding to the datum. The invention also relates to a data transmission method and to an electronic circuit configured to implement said methods.