It is next to "Protocol Exploitation," so it could be anything from "Data" to "Public Key."

What I am wondering at the moment is the "DNI" on the same slide, is this direct neural interface? /tinfoil

Though I can't look at the slide, DNI should stand for Director of National Intelligence.

"Decryption" would be my guess. I don't buy the explanation WaPo offers for "Protocol Exploitation" because the name itself is so suggestive...