The Stream Cipher HC-128
Hongjun Wu · 2010
Statement 1. HC-128 supports 128-bit key and 128-bit initialization vector. Statement 2. 2 64 keystream bits can be generated from each key/IV pair. Statement 3. There is no hidden flaw in HC-128. Statement 4. The smallest period is expected to be much larger than 2 128. Statement 5. Recovering the secret key is as difficult as exhaustive key search. Statement 6. Distinguishing attack requires more than 2 64 keystream bits. Statement 7. There is no weak key in HC-128. Statement 8. Encryption speed is 3.05 cycles/byte on Pentium M processor. Statement 9. The key and IV setup takes about 27,300 clock cycles Statement 10. HC-128 is not covered by any patent and it is freely available. Remarks. When more than 2 64 keystream bits are generated from each key/IV pair, the effect on the security of the message/key is negligible. Thus there is no need to implement any mechanism to restrict the keystream length in practice. 1