An Enhanced User Authentication Protocol Based on Elliptic Curve Cryptosystem in Cloud Computing Environment

Table 1

Notations and abbreviations.

Symbol	Description
	user
	cloud server
	the register authority
	the adversary
	the long term secret key of
	the secret key of
	identity of
	password of
	identity of
	shared key between and
	bitwise XOR operation
	concatenation operation
	one-way hash function
	a common channel
	a secure channel