## Cryptology ePrint Archive: Report 2015/684

A One-time Stegosystem and Applications to Efficient Covert Communication

Aggelos Kiayias and Yona Raekow and Alexander Russell and Narasimha Shashidhar

Abstract: We present the first information-theoretic steganographic protocol with an asymptotically optimal ratio of key length to message length that operates on arbitrary covertext distributions with constant min-entropy. Our results are also applicable to the computational setting: our stegosystem can be composed over a pseudorandom generator to send longer messages in a computationally secure fashion. In this respect our scheme offers a significant improvement in terms of the number of pseudorandom bits generated by the two parties in comparison to previous results known in the computational setting. Central to our approach for improving the overhead for general distributions is the use of combinatorial constructions that have been found to be useful in other contexts for derandomization: almost $t$-wise independent function families.

Category / Keywords: cryptographic protocols / Information hiding, steganography, data hiding, steganalysis, covert communication

Original Publication (with minor differences): IACR-JOC-2014
DOI:
10.1007/s00145-012-9135-4

Date: received 7 Jul 2015, last revised 4 Jan 2016

Contact author: karpoor at shsu edu

Available format(s): PDF | BibTeX Citation

Short URL: ia.cr/2015/684

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