A Secure Fair Exchange for SMS-Based Mobile Payment Protocols Based on Symmetric Encryption Algorithms with Formal Verification

Table 2

Symbols and abbreviations.

Symbol	Definition	Bits
//IMSI	International Mobile Subscriber Identity of Mobile station	80
MAC/H	Message Authentication Code/Hash function	160
ReqNo/Seq	Request number	8
DK	Delegation key	128
Order_msg	Product order	160
Price/P	Cost of product	64
Withdraw_Req_Msg/ Withdraw_Resp_Msg	The customer pays the desired price from his bank	64
Ack	A validation message to the customer	64
FS	Financial server identification	128
Name	Name of payer	160
NationalID	National Identification	104
RandomPublicKey	The ephemeral public key	128
PayeeMobNo	Mobile phone number of payee	80
Value	Digital currency	80
///	Identification of Payer/ Payee/Client/Merchant	80
Payee_Id	Identification of Payee	80
BI	Bank information	128
Amt	Amount in payer’s bank account	64
/// /////; ////K/Passkey/UAKey	Session Key	128
//// T/T1/T2/T3/T4/T5	Timestamp	80
///	Nonce	128
Payment_Notify	Payment acknowledgment	128
	Payment Information of payer	128
TID	Transaction ID	128
ExpT/Expiry/KeyExpiry	Expiry of primary key	64
/	Random number	128
	Certificate of Security Access Gateway	40
ID_ME	Mobile phone Number	80
	Certificate of mobile phone	40
SN	Serial number of the top-up cash card	112
	Credit limit	40
	Remaining credits	40
OI/Order_Message	Order information	160
(Yes/No)	Purchase credit request/Message status of merchant verifies the goods or services	24
(Accept/Reject)/Req_Msg	Payment status	48