It was more in terms of comparison with security strength vs key length. For example, 3072 bit RSA keys are equivalent in security strength to 128-bit symmetric

It was more in terms of comparison with security strength vs key length. For example, 3072 bit RSA keys are equivalent in security strength to 128-bit symmetric keys. To reach 256-bit security strength equivalence, you need 15360-bit RSA keys. [1](Page 63) 1. http://csrc.nist.gov/publications/nistpubs/800-57/sp800-57-Part1-revised2_Mar08-2007.pdf http://csrc.nist.gov/publications/nistpubs/800-57/sp800-57-P...