In 1990 and 1991, the US government became concerned that the marketing of a secure telephone system by AT&T could curtail Comint activity. AT&T was persuaded to withdraw its product. In its place the US government offered NSA "Clipper" chips for incorporation in secure phones. The chips would be manufactured by NSA, which would also record built-in keys and pass this information to other government agencies for storage and, if required, retrieval. This proposal proved extremely unpopular, and was abandoned. In its place, the US government proposed that non government agencies should be required to keep copies of every user's keys, a system called "key escrow" and, later, "key recovery". Viewed in retrospect, the actual purpose of these proposals was to provide NSA with a single (or very few) point(s) of access to keys, enabling them to continue to access private and commercial communications.