Cryptographic techniques authenticate users and protect information confidentiality. These tasks are performed by subsystems called Oracles. The most popular is the RSA system based on two large primes granting secure services. In 2008, a programming error in Open-SSL of the Debian system was detected. Its number generator was biased and creating system vulnerabilities by turning certificates predictable. This paper analyses the generic performance of a RSA cryptographic Oracle and develops a methodology to detect irregularities and anomalies in the quality of the certificates. A solution is presented to identify possible colliding primes. In this way, network administrators and information security experts can audit the performance of cryptographic modules in use.Sociedad Argentina de Informática e Investigación Operativa