Full key dependent coverless test disguise method by interval-extension-based double authentications

Abstract

In traditional search-based coverless information hiding methods, there are some problems such as the low hidden capacity, high cost of database creation and search, dense transmission of data, and absence of authentication. To avoid these problems, we propose a full key dependent coverless test disguise method by interval-extension-based double authentications. We transform secret information into a coded sequence by a random codebook sequence that is generated by user keys. The initialized codebook sequence is used to hinder the direct transmission of secret information. Then, we use candidate answers’ orders and question set indexes to express the coded index sequence. In the restoration process, the extracted information can be authenticated efficiently by the legal interval and a comparison. The experimental results and analysis show that our method achieves a high hidden capacity with a simpler test database, avoids dense transmission of data and authenticates extracted information well. Without the correct user keys, the secret information cannot be acquired.