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

Table 7

Symbols used in performance analysis.

Symbol	Meaning
𝑙𝑁	Length of ⟨𝒰⟩, |ID𝒰𝑗|, |𝑇|, |VT|, and each command (e.g., 32 bits)
𝑙𝐻	Length of the output of hash function (e.g., 128 bits)
𝑙𝐾	Length of a symmetric key 𝒦𝒰𝑗 (e.g., 128 bits)
𝑙𝑊	Length of |𝑤𝒮𝑖| and |𝑤𝒰𝑗| (e.g., 1024 bits)
𝑙𝐸	Length of |MK𝒰𝑗| and |EMK𝒰𝑗| (e.g., 6⋅𝑙𝑁 + 𝑙𝑊 = 1184 bits)
𝑇𝑀	The cost of running MAC algorithm
𝑇𝐶	The cost of running the comparison or element-existence checking
𝑇𝐸	The cost of running the symmetric-key encryption function
𝑇𝐷	The cost of running the symmetric-key decryption function
𝑇𝑋	The cost of running the module exponential computation

Note: normally, 𝑇_𝑀<𝑇_𝐶<𝑇_𝐸≈𝑇_𝐷<𝑇_𝑋, and 𝑙_𝑁<𝑙_𝐻≈𝑙_𝐾<𝑙_𝑊<𝑙_𝐸.