Safe primes density and cryptographic applications

Safe prime number deployment has proved to be a major concern when developing public key cryptographic applications. Most popular public key cryptosystems (PKC) are rooted in the grounds of a high-quality safe prime number generator being available. For instance, RSA-present almost anywhere a PKC is needed-is claimed to need the so-called "strong primes", related to safe primes. Similarly, BBS (the Blum-Blum-Shub PKC) is founded on pseudo-random number generation by means of the so-called BBS generator, whose maximal length orbits are obtained precisely when 2-safe primes, verifying some other suitable conditions, are used to build up the congruence modulus. Interest in this type of number encourages research into its density and methods of computation. We present an estimate for the density of both 1-safe and 2-safe prime numbers.