[Retracted] A Lightweight Proxy Re-Encryption Approach with Certificate-Based and Incremental Cryptography for Fog-Enabled E-Healthcare

Table 1

Notations of the proposed scheme.

Serial no.	Notation	Description
1	IDU	Unique identity of user
2	E	Security parameter
3	CA	Certificate authority
4	Q	It is a large prime number
5	δ	Generator point
6	δ	Master secret key
7	MPk	Master public key
8	Ψ	Set of public parameters
9	CertU	User certificate
10	α, β, γ	Random values
11	S	Digital signature
12	HP U	Public key hash
13	KU	Private key
14	PU	Public key
15	RA⟶B	Re-encryption key
16	HER	Electronic health record
17	Z	Total number of blocks of a file
18	Bk	kth block of the FILE
19	Dj	Size of the jth block
20	FS	Total size of the FILE
21	Ck	Ciphertext of kth block
22	C	Ciphertext of entire file
23	CA	A number χ PKA
24	CB	A number χ PKB
25	MACk	MAC value of Bk block
26	MACfinal	Final mac value of all z blocks
27	Bupdate	Ciphertext of updated block
28	Cupdate	Block that user want to update
29	h1	Hash function
30	KCertA	Certificate authority private key