Since the mid-1990s, data hiding has been proposed as an enabling technology for securing multimedia communication, and is now used in various applications including the monitoring of broadcast, film prints, steganography, video indexing and retrieval, and image authentication. Data hiding and cryptographic techniques are often combined to complement one another, thus triggering the development of a new research field of multimedia security. In addition, two related disciplines, steganalysis and data forensics, the more attractive and become a new study researchers in other fields of multimedia security. This journal, LNCS Transactions on Data Hiding and Multimedia Security, aims to become a forum for researchers in this field appears, publishing both original and archival research. The second issue contains five papers dealing with various topics related to multimedia security.