Analysis and Improvement of Blockchain-Based Multilevel Privacy-Preserving Location Sharing Scheme for Telecare Medical Information Systems

Algorithm 3

Location sharing.

	Input:
	Location record ID ; Session key between LDO and LDR ; Privacy protection level ; LDR’s public-key
	Output:
	Shared location information
(1)	LDR executes:
(2)	;
(3)	LDR sends to LDO;
(4)	LDO executes:
(5)	ifthen
(6)
(7)	else ifthen
(8)	find the border in level
(9)	;
(10)	;
(11)	;
(12)	;
(13)	;
(14)	;
(15)	;
(16)
(17)	end if
(18)	return.