A paper presented at the ICICS 2019 conference describes what is claimed to be a `provably secure group authentication [protocol] in the asynchronous communication model'. We show here that this is far from being the case, as the protocol is subject to attacks breaking the security model. To try to explain this troubling case, an earlier (2013) scheme on which the ICICS 2019 protocol is based was also examined and found to possess even more severe flaws -- this latter scheme was previously known to be subject to attack, but not in quite as fundamental a way as is shown here. Examination of the `proofs' of the security `theorems' provided in both the 2013 and 2019 papers reveals that in neither case are the proofs rigorous; the issues raised by this are also briefly discussed.

翻译：在ICICS 2019年会议上提交的一份文件描述了所谓“非同步通信模式中可能安全的集体认证[规 ”的说法。我们在这里表明,情况远非如此,因为协议受到破坏安全模式的攻击。为了解释这一令人不安的案例,还审查了ICICS 2019年协议所依据的早期(2013年)计划,发现该计划存在甚至更严重的缺陷 -- -- 后一种计划以前已知会受到攻击,但不像这里所显示的那样具有根本意义。对2013年和2019年文件所提供的安全`理论'的“证据”的审查表明,在这两个文件中,证据都不严格;对此提出的问题也进行了简要讨论。