Internet of Things Security: Challenges and Key Issues

Table 2

Classification of some IoT authentication schemes.

Protocol	Proposed for securing		Method used
	IoT	WSN	Encryption algorithm	Random number	Hash function	Others
[128]	—	✓	—	—	✓	—
[129]	✓	—	—	—	—	Time synchronization
[110]	✓	—	ECC	—	—	Lamport’s OTP algorithm
[109]	—	—	—	✓	—	Zero-knowledge proof
[104]	—	—	AES-based MAC	—	—	—
[130]	✓	✓	ECC	—	✓	—
[131]	✓	✓	ECC	—	✓	Smart card
[132]	✓	—	ECC	✓	✓	—
[133]	✓	—	—	—	✓	—
[134]	✓	—	AES	—	—	—
[83]	✓	—	Symmetric encryption	—	—	—
[15]	✓	—	—	✓	✓	Fuzzy extractor mechanism
[20]	✓	—	ECC	✓	✓	Challenge-response
[135]	✓	—	Symmetric encryption	✓	✓	Blockchain machine learning
[136]	✓	—	ECC	✓	✓	-

ECC: elliptic curve cryptography; AES: Advanced Encryption Standard; OTP: one time password; WSN: wireless sensor network.