At Eurocrypt'95 Sako and Kilian presented the first Mix-type voting scheme which is receipt-free and universally verifiable.
In this contribution we analyze this scheme and show that the coercer must not collude with any center. Otherwise its robustness is lost. As a result, the assumed coercer model is clarified. More seriously, it is further pointed out that the privacy of votes can't be guaranteed, if only one Mix-center is honest. Hence, under the commonly used assumption that only one Mix-center must be honest, the voting scheme is insecure unless modified.