Figure A.1 shows the translation from λ→ to λ ⇓ ` including the insertion of origin markers, and is otherwise identical to Figure 3. Similarly,Figure A.2 shows the single-step reduction rules for λ` with origin markers p included; otherwise it is identical to the rules shown in Figure 4. Figure A.3 shows the precision relations for λ` and λ ? → used in proving the gradual guarantee. Figure A.4 ...

News articles in 2014 stated that 1.8 billion images are uploaded daily to the Internet, and this number is expected to increase annually. However, some of these uploaded images may contain hidden information that can potentially be malicious (e.g. an image that contains hidden information regarding terrorism recruitment) or may cause serious damage (e.g. an employee wishing to hide sensitive c...

The least significant-bit (LSB) based techniques are very popular for steganography in spatial domain. The simplest LSB technique simply replaces the LSB in the cover image with the bits from secret information. Further advanced techniques use some criteria to identify the pixels in which LSB(s) can be replaced with the bits of secret information. In DCT based technique insertion of secret info...

In the present study, we present a new steganography technique for hiding data in images using parity checker. This method uses the concept of odd and even parity for insertion and retrieval of message. This method is an improvement over earlier methods like least significant bit method and 6th, 7th bit method [1] for hiding information in images. Our method retains the advantages of above meth...