SSC2 is a fast software stream cipher designed for wireless handsets with limited computational capabilities. It supports various private key sizes from 4 bytes to 16 bytes. All operations in SSC2 are word-oriented, no complex operations such as multiplication, division, and exponentiation are involved. SSC2 has a very compact structure that makes it easy to implement on 8-,16-, and 32-bit processors. Theoretical analysis demonstrates that the keystream sequences generated by SSC2 have long period, large linear complexity, and good statistical distribution.