  Steganography is a solution for covert communication and blockchain is a p2p
network for data transmission, so the benefits of blockchain can be used in
steganography. In this paper, we discuss the advantages of blockchain in
steganography, which include the ability to embed hidden data without manual
change in the original data, as well as the readiness of the blockchain
platform for data transmission and storage, which eliminates the need for the
Steganographer to design and implement a new platform for data transmission and
storage. We have proposed two algorithms for steganography in blockchain, the
first one is a high-capacity algorithm for the key and the steganography
algorithm exchange and switching, and the second one is a medium-capacity
algorithm for embedding hidden data. Also, by reviewing the previous three
steganography schemes in blockchain, we have examined their drawback and have
showed that none of them are practical schemes for steganography in blockchain.
Then, we have explained the challenges of steganography in blockchain from the
steganographers and steganalyzers point of view.
