A Secure Certificateless Signature Scheme for Space-Based Internet of Things

Table 1

Existing works.

Method	Main mechanism	Services	Shortcomings
PKI	Public key certificate, certificate authority (CA), registrar authority (RA), etc.	Authentication, integrity, confidentiality, data fairness, nonrepudiation	Certificate management consumes a lot of resources
IBC	User ID is the user’s public key (which can be their name, IP address, e-mail address, mobile phone number, etc.)	Authentication, integrity, confidentiality, and nonrepudiation	Key escrow issue
CL-PKC	The user’s private key is divided into two parts; one is generated by KGC, and the other is generated by the user	Authentication, Integrity, Confidentiality, and nonrepudiation	Some existing schemes have low security or high overhead; it is not fully considered for S-IoT scenarios