A secure random number generator can seed itself with unpredictable values and produce cryptographically strong pseudo-random numbers suitable for generating cryptographic keys. 
Retrieving the list of available secure random number generators requires checking the services provided by all registered providers. The retrieved list of names can be used in creating a SecureRandom object. 

    // This method is implemented in e194 Listing All Available Cryptographic Services
    String[] names = getCryptoImpls("SecureRandom");

An example of the output: 
    SHA1PRNG