largely eclipsed this device, and it is no longer widely used. HY-2 a vocoder for long haul circuits designed to work with the KG-13 key generator. Secure Terminal Equipment (STE) – This system is intended to replace STU-III. It uses wide-bandwidth voice transmitted over ISDN lines. There is also a version which will communicate over a PSTN (Public Switched Telephone Network) line. It can communicate with STU-III phones and can be upgraded for FNBDT compatibility. Sectéra Secure Module – A module that connects to the back of a commercial off the shelf cellular phone. It uses AES or SCIP for encryption. OMNI – The OMNI terminal, made by L3 Communications, is another replacement for STU-IIIs. This device uses the FNBDT key and is used to securely send voice and data over the PSTN and ISDN communication systems. VINSON A series of systems for tactical voice encryption including the KY-57 man portable unit and KY-58 for aircraft HAVE QUICK and SINCGARS use NSA-supplied sequence generators to provide secure frequency hopping Future Narrowband Digital Terminal (FNBDT) – Now referred to as the "Secure Communications Interoperability Protocol" (SCIP), the FNBDT is a replacement for the wide-band STE, which uses narrow-bandwidth communications channels like cellular telephone circuits, rather than ISDN lines. The FNBDT/SCIP operates on the application layer of the ISO/OSI Reference Model, meaning that it can be used on top of different types of connections, regardless of the establishment method. It negotiates with the unit at the other end, much like a dial-up modem. Secure Iridium – NSA helped add encryption to the Iridium commercial mobile phones after it rescued the bankrupt Iridium. Fishbowl – In 2012, NSA introduced an Enterprise Mobility Architecture intended to provide a secure VoIP capability using commercial grade products and an Android-based mobile phone called Fishbowl that allows classified communications over commercial wireless networks. The operational complexity of secure voice played a role in the September 11, 2001 attacks on the United States. According to the 911 Commission, an effective U.S. response was hindered by an inability to set up a secure phone link between the National Military Command Center and the Federal Aviation Administration personnel who were dealing with the hijackings. See Communication during the September 11, 2001 attacks. Internet NSA has approved a variety of devices for securing Internet Protocol communications. These have been used to secure the Secret Internet Protocol Router Network (SIPRNet), among other