The Number Field Sieve (NFS) is a:

A.
General purpose factoring algorithm that can be used to factor large numbers

B.
General purpose algorithm used for brute force attacks on secret key cryptosystems

C.
General purpose hash algorithm

D.
General purpose algorithm to calculate discreet logarithms

Explanation:
The NFS has been successful in efficiently factoring numbers larger than 115 digits and a version of
NFS has successfully factored a 155-digit number. Clearly, factoring is an attack that can be used
against the RSA cryptosystem in which the public and private keys are calculated based on the
product of two large prime numbers. The other answers are distracters.