The Fail-stop signature is a very secure system, even though the attacker gains signature key, it is difficult to forge signature.

防失败签字是一种十分安全的签字体制，即使攻击者得到签字密钥后也难以伪造签字。

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"That's a very secure system in ensuring that the person who does apply for the vote is the genuine voter, " she said.

BBC: NEWS | UK | UK Politics | UK post vote fraud claims probed

We're dealing with gangs of people who are making billions of pounds out of forged passports and that's why our system has to be very secure.

BBC: Fewer fake passports being found by UK's border force