Research Article

IBE-Signal: Reshaping Signal into a MITM-Attack-Resistant Protocol

Table 2

Abbreviations and notations.

Abbreviations/notationsMeaning

Secure parameter
Big prime
Additive group on an elliptic curve of the order
Multiplicative group on an elliptic curve of the order
Bilinear function
Generator of the group
The private key, the public key, and the shared public key of the KGC
The private key, the public key, and the shared public key of the CPC
The shared public key of the CPCn that equals to
A secure hash function that takes a string of any length as input and gives an element on
A secure hash function that takes an element on and gives a string of length
A secure hash function that takes a string of length and gives a string of length
A secure hash function that takes a string of any length and gives an element on
A secure hash function that takes a string of any length and an element on and gives an element on
A secure hash function that takes two strings of length and gives a string of length
Secure key derivation function that takes an element on and a string of length and gives a string of length
Number of users
Initially empty revocation list
A binary tree with at least leaf nodes representing states
Minimum time interval
The private key of key authority
Part of the system parameter of key authority and
System parameter of the KGC
System parameter of the CPCs
System parameter of key authority
The final public parameter in the setup step
Identity of the receiver
Identity of the sender
Mapping of on
Mapping of on
The private key of the receiver
The private key of the sender
Mapping of on
The time when the encryption occurs
Mapping of on
The input of the root chain in the double ratchet algorithm
Revocation key
The input of the root chain in the CONNECTION part of the IBE-signal scheme
Message key for the encryption of the first message
Blinding factor in the private key issuance process
Timestamp used to prevent replay attacks
Receiver’s local time
The message that needs to be signed
Signature
Private keys for revocation
Key updates for revocation
Revocation key selected from and
Bob’s public and private keys in Diffie–Hellman key exchange in CONNECTION part
Alice’s public and private keys in Diffie–Hellman key exchange in CONNECTION part
The message key of the sender in the session
The message key of the receiver in the session