Authenticated Blind Issuing of Symmetric Keys for Mobile Access Control System without Trusted Parties

Table 1

Notations.

Notation	Meaning
⟨𝒜⟩	Administrator status
⟨𝒮⟩	Super user status
⟨𝒰⟩	Normal user status
⟨𝒢⟩	Guard system status
ℳ𝒦	Master grade authentication key
𝒱𝒦	Visitor grade authentication key
ID𝑈	Entity identity 𝑈
𝑇𝑈	Time stamp used for an entity 𝑈
VT𝑈	Validity time of an entity 𝑈
𝐸𝑘(𝑥)	Encryption of message 𝑥 using symmetric key 𝑘
𝐷𝑘(𝑥)	Decryption of message 𝑥 using symmetric key 𝑘
𝐻𝑘(𝑥)	Hash value of message 𝑥 using hash function 𝐻 and key 𝑘
|𝑥|	Bit length of message 𝑥