Comment by doetoe

That is not when an encryption algorithm is usually considered to be broken, it just means that a certain key length is not sufficient anymore. You can break 20 bit RSA with pen and paper, but as long as a linear change in the key length causes an exponential increase in the decryption time, the algorithm is not broken. At this moment, the record for the factorization of a specific RSA key is one of 829 bits, which suggests (by extrapolation) that within a few decades 1024 bits may not be safe if your adversary has the resources. No (reasonable) key length can be expected to be safe forever, even without any mathematical breakthroughs