Analysis and Improvement on an Authentication Protocol for IoT-Enabled Devices in Distributed Cloud Computing Environment

Table 1

Notations table.

Symbol	Description
CS	The control server
	mth cloud server
	Identity of the mth cloud server
	Random number of
	ith user
	Identity of the user
	Password of the user
	Two random numbers of
	Secret numbers of CS
	Hash function
	Timestamp
	Bit-wise xor operation
||	Concatenate operation