Covert Communication Scheme Based on Bitcoin Transaction Mechanism

Table 1

Notations.

Notations	Description
M	Secret information
K	Key (as the private key of the input address)
K	Symmetric key
C	Secret information ciphertext
R	Random number
||	The operator to concatenate two strings
Hash_Pk	Public key hash
Hash_Pks	Special public key hash (embedded information)
A	Normal address
As	Special address (as output address)
AK	The address generated with the key K as the private key (as the input address)
Ts	Special transaction
Fees	The fee of special transaction
Tdp	The transaction that causes double-spend conflict
Feedp	The fee of transaction that causes double-spend conflict
ID_Ts	The ID of special transaction
ID_Tdp	The ID of transaction that causes double-spend conflict
Create_Addr	Function of generation bitcoin address
Base58Check	Generate a bitcoin address from the public key hash
Create_T_Broadcast	Function of create and broadcast transactions in bitcoin
GetTransaction	The blockchain API, get transaction information related to the specified address