Methods are provided for encoding watermark information into media data containing a series of digital samples in a sample domain. The methods involve: dividing the series of digital samples into a plurality of sections in the sample domain, each section comprising a corresponding plurality of samples; processing the corresponding plurality of samples in each section to obtain a single energy value associated with each section; grouping the sections into groups, each group containing three or more sections; for each group, assigning a nominal bit value according to a bit assignment rule, assigning a watermark bit value and comparing the watermark bit value to the nominal bit value. If the nominal bit value and the watermark bit value do not match, modifying one or more energy values of one or more corresponding sections in the group where re-application of the bit assignment rule would assign the watermark bit value to the group.

A method for picture-based barcode encoding and decoding is provided herein. The method for picture-based barcode encoding includes: transforming an original data into an original data bitstream; performing an error correction on the original data bitstream for translating the original data bitstream into an error corrected bitstream; selecting all or part of the picture as an encoded area; calculating a data storage capacity of the encoded area; adjusting a size of the error corrected bitstream or a size of the encoded area for equalizing a data storage capacity of an encoded data bitstream and the data storage capacity of the encoded area; and adjusting a pixel value of the encoded area according to the encoded data bitstream.

The disclosure relates to message encoding. One claim recites an apparatus comprising: an input to receive a message key for transforming a plural-bit message, the message key having been generated through transforming a multi-bit seed with a randomizing process, and encoding the transformed multi-bit seed with error correction encoding, the transforming and encoding yielding the message key; electronic memory for storing a plural-bit message; and an electronic processor programmed for transforming the plural-bit message with the message key to yield a transformed message, and programmed as an encoder for encoding the transformed message key in data representing audio or imagery, thereby transforming the data representing audio or imagery. Of course, other claims and combinations are provided too.

According to one embodiment, an image processing device includes storage means, encryption means, and output means. The storage means stores an encryption key in correlation with a built-in application during installation of the built-in application. The encryption means encrypts a debug log relating to the built-in application with the encryption key in correlation with the corresponding built-in application. The output means outputs the debug log encrypted by the encryption means.