A variety of different clock-controlled stream ciphers and attacks on them have been described in a number of papers. However, few word-oriented algorithms with an irregular clocking mechanism have been proposed. This paper proposes a new design of irregular clocking for word-oriented stream ciphers that is dynamic feedback control and show analysis results of its security and performance. The stream cipher K2 v2.0 is a secure and high-performance stream cipher using the dynamic feedback control, which is applicable for several applications. We believe that the dynamic feedback control mechanism is potentially effective against several different types of attacks, not only existing attacks but also novel attacks.