2011 年 E94.A 巻 1 号 p. 367-382
It is known that composable secure commitments, that is, concurrent non-malleable commitments exist in the plain model, based only on standard assumptions such as the existence of claw-free permutations or even one-way functions. Since being based on the plain model, the deniability of them is trivially satisfied, and especially the latter scheme satisfies also adaptivity, hence it is adaptive-deniable-concurrent non-malleable. However, those schemes cannot be said to be practically efficient. We show a practically efficient (string) adaptive-deniable-concurrent commitment scheme is possible under a global setup model, called the Global CRS-KR model.