Side-Channel Attacks and Countermeasures for Identity-Based Cryptographic Algorithm SM9

Table 5

Countermeasures and overhead. Cost estimation: negligible (<10%), low (10%–50%), and high (>50%).

Countermeasures	Target attacks	Computation overhead
Indistinguishable point operation	SPA	Low
Double-and-add-always	SPA	Low
Atomic block	SPA	Negligible
Montgomery ladder	SPA	Low
Random splitting	SPA	High
Base point blinding	Template attack	Negligible
Random projective coordinates	Template attack	Negligible
Random EC isomorphism	Template attack	Low
Random field isomorphism	Template attack	Low
Point validation	Fault attack	Negligible
Curve integrity check	Fault attack	Negligible
Coherence check	Fault attack	Low
Combined curve check	Fault attack	Low
Security curve selection	Fault attack	-