In RFID protocols, random numbers are mainly required to anonymize tag answers in order to guarantee the privacy of the owner of the transponder. Our analysis looks at the feasibility of RFID tags for supporting Cryptographically Secure Pseudorandom Number Generators (CS-PRNG) on their limited chip. Specifically, we study the implementation of the Blum-Blum-Shub (BBS) pseudorandom number generator for security levels 2³² (160 bits) and 2⁶⁴ (512 bits) respectively, these values being suitable for many RFID applications but not for standard security applications.