BBN's next network security R&D effort was the BCR (standing for black-crypto-red). This was not an NSA-approved system. Of the BCR, Steve Kent has said, "In the 1975-1980 timeframe, BBN, University of Texas Austin, and the Collins Radio division of Rockwell developed and did limited deployment of the BCR, also under ARPA funding, as an experimental network encryption device. The BCR worked in the TCP/IP protocol environment, used the first NBS-certified DES chips, and had automated, KDC-based key management and access control (the same model later adopted by Kerberos and Blacker). The BCR underwent substantial performance testing in 1980-81, before being retired."