It's very probable that they have and if so, it's almost certain that it would involve specialized hardware implementations (ASIC, FPGA, whatever) rather than c

It's very probable that they have and if so, it's almost certain that it would involve specialized hardware implementations (ASIC, FPGA, whatever) rather than commodity graphics hardware which is burdened with expensive and useless stuff like onboard memory and would be power inefficient considering that the entire purpose of NSA in the first place is to provide SIGINT and encrypt or decrypt signals, it's almost a given that they're trying to the best of their ability to crack stuff.