The concept of encrypted information hiding has been presented. The use of cryptographic algorithms together with steganography and watermarking methods make it almost impossible for interceptor to recover the encrypted hidden data as this requires the interceptor to detect the existence of the information before attempting to decrypt it. To recover the original data, the attacker needs to first find a way to extract the hidden encrypted information from the stego-data, which requires knowledge of the data hiding codes and the appropriate algorithm/key(s). The exposure of the encryption key(s), the encryption algorithm and the embedding technique along with the hidden codes to those other than the intended receiver is practically impossible. A watermarking scheme is described that combines lossless compression and encryption for medical imaging applications. The authors proposed that a doctor/radiologist is interactively provided with a defined polygonal Region of Interest (ROI). The data is encrypted using Advanced Encryption Standard (AES) algorithm, and then the watermark is compressed using an arithmetic integer compression method. The compressed data is then converted to a binary string and embedded in the image using the bit-plane specified by the user. The authors proposed a steganographic method using PNG formatted images based on an information sharing technique. The secret image M is divided into shares which are embedded into the alpha-channel of the PNG host image. A virtually imperceptible image hiding scheme based on vector quantization (VQ) is proposed. The author’s goal was to design a high quality and a high capacity image hiding scheme which is based on the VQ compression and a Digital Encryption Standard (DES) based cryptosystem. The approach to digital watermarking based on the use of cryptography in conjunction with watermarking is presented.