Abstract:Advanced Encryption Standard (AES) is the current encryption standard adopted by U.S. government and plays an important role in cryptograph systems. Meanwhile, Radar signal transmission requires reliability, high throughput and high security, which rise the demands of adapting AES as a stream cipher. Hereby, by redesigning the CTR mode, AES as a stream cipher is achieved. The architecture folding and algorithm reuse improve the throughput and keep the resource utilization low. On-the-fly key scheduling, pure logic S-Box, distributed share memory and pipeline processing are achieved in small FPGAs. The real-life test shows the design satisfies the requirements of Radar signal encryption.