Patent attributes
A first lawful interception (LI) function transmits, to a second LI function in a virtualized network function, VNF, a request for random number generator, RNG, data, characterizing a random number generator in the second LI function. The RNG data is tested, resulting in a randomness test result that is indicative of randomness of numbers generated by the RNG in the second LI function. If the randomness is below a first threshold, mitigation takes place of any undesired effect associated with the randomness being less than the threshold value. A corresponding method is performed by the second LI function, receiving the request for RNG data, obtaining and transmitting the RNG data to the first LI function. Verification can thereby be made whether a LI function in a VNF has a proper level of entropy source for use by its cryptographic operations and, if not, perform mitigation.