code: public static BigInteger getSafePrime(UnsignedInteger32 maximumSize) {
  
  		BigInteger prime = group1;
  		for(Iterator<BigInteger> it = safePrimes.iterator(); it.hasNext(); ) {
  			BigInteger p = it.next();
  			int len = p.bitLength();
  			if(len > maximumSize.intValue()) {
  				break;
  			}
  			prime = p;
  		}
  		
  		return prime;
  	}
docs: get the biggest safe prime from the list that is <= maximumSize
  
  @param maximumSize
  @return BigInteger