That is true for symmetric encryption, but not for asymmetric encryption. If I recall correctly, for RSA based asymmetric encryption you are increasing the key space from the number of 1,023 bit prime numbers to the number of 1,024 bit prime numbers. For symmetric encryption you increase the key space from the number of 1,024 bit numbers to the number of 1,025 bit numbers. What they should really do is switch to ECC. Much faster than RSA, much smaller keys, superior properties over all. RSA is kind of outdated these days.