A Blockchain-Based Personal Health Record System for Emergency Situation

Table 2

Explanation of notations in different transaction processes.

Notation	Description
PID	The ID represents patient’s identity
DID	The ID represents doctor’s identity
AnonymityID	The patient’s anonymous identity
HNumber	The number of doctors’ hospitals
pk , sk	The patient’s public key and private key
pk , sk	The doctor’s public key and private key
Num	Length of the generated symmetric key
K	AES symmetric key
C	Original PHR file
C′	Updated PHR file
C	File with symmetric encrypted PHR
	Updated symmetric encrypted PHR file
	File with encrypted K
	File with reencrypted EnK
Ensk	The patient’s cyclically encrypted private key
EnK	K’s ciphertext after being encrypted by PK
EnK′	EnK’s reencrypted key
Hash	Hash value returned by IPFS uploading file C
Hash	Hash value returned by IPFS uploading file C
Hash	Hash value returned by IPFS uploading file