A² Chain: A Blockchain-Based Decentralized Authentication Scheme for 5G-Enabled IoT

Table 2

Security comparison of different schemes.

	[37]	[17]	[18]	[28]	[29]	[50]	A^2 Chain
Sybil	✓	✓	✓	✓	✓		✓
Message replay	✓	✓	✓	✓	✓		✓
DOS		✓	✓	✓	✓	✓	✓
Scalability	✓	✓		✓	✓	✓	✓
Cross-domain authentication	✓					✓	✓
Decentralization	✓	✓	✓	✓	✓	✓	✓