Their goal is to collect and archive the data, much of which is plaintext anyway. With plans to archive it for 100 years, they can just simply wait until vulne

Their goal is to collect and archive the data, much of which is plaintext anyway. With plans to archive it for 100 years, they can just simply wait until vulnerabilities in block ciphers are discovered (possibly by the NSA) and hold on to the data until then and decrypt it. I'm sure they're decrypting everything they know how, but for everything else, it's just archival.