Table 2.

Consensus Protocol Comparison.

	PoW	PoS	PoET	BFT and Variants	Federated BFT
(i) BC type	Permissionless	Both	Both	Permissioned	Permissionless
(ii) Transaction finality	Probabilistic	Probabilistic	Probabilistic	Immediate	Immediate
(iii) Transaction rate	Low	High	Medium	High	High
(iv) Token needed?	Yes	Yes	No	No	No
(v) Cost of participation	Yes	Yes	No	No	No
(vi) Scalability of peer network	High	High	High	Low	High
(vii) Trust model	Untrusted	Untrusted	Untrusted	Semi-trusted	Semi-trusted