The present invention relates to a method of converting an encrypted data set into an encryption of individual bits representing the data set. Further, the invention relates to a system for converting an encrypted data set into an encryption of individual bits representing the data set. A basic idea of the present invention is to provide a protocol in which it is possible to divide an encryption of a data set in the form of e.g. a biometric feature, such as a number x, where xε{0, 1, . . . , n−1}, into an encryption of respective bits x0, x1, . . . , xt-1 forming the number x, where t is the number of bits of the number n−1, without leaking any information about x or its bits x0, x1, . . . , xt-1 Hence, the present invention enables splitting of the encryption [[x]] into the respective encrypted bits [[x0]], [[x1]], . . . , [[xt-1]] forming the encrypted number x=ΣI=1n xi 2i.