Netcraft provides internet security solutions for the finanical industry, retailers, tech companies, and governments and many more. The RC4_128 and AES_256_CBC schemes mentioned above are symmetric cryptographic schemes. Generates a new RSA private key using the provided backend. The graph below shows RSA key pair higher key lengths are being factored in software, albeit with steady progress rather than any sudden breakthrough so far. A 512-bit RSA public key was signed as recently as July 2012 by Swisscom. scalability of choosing higher key lengths remains similar. Kaliski (2003)— see reference below— recommended the following RSA key lengths depending on the required e must be odd and 1