Table 6.

Security features.

Scheme	SF
	1	2	3	4	5	6	7	8	9	10	11	12	13
[22]	√	×	√	√	×	√	√	×	×	×	√	×	×
[24]	√	√	√	√	√	√	×	×	×	×	√	×	√
[26]	√	√	√	√	√	√	√	√	√	√	√	×	√
[37]	√	√	√	√	√	√	×	×	√	√	×	×	√
[38]	√	√	√	√	√	√	×	×	√	√	√	×	√
Ours	√	√	√	√	√	√	√	√	√	√	√	√	√