This can be realized by adopting an integrated approach usingcompression and encryption techniques, such a system is termed as crypto compression system. Lossy compression reduces the size of a file by removing certain data. We present new and general constructions of lossy encryption schemes and of cryptosystems secure against selective opening adversaries. Bellare, hofheinz and yilek showed that lossy encryption is also selective opening secure. Data compression fundamentals of data representation. Lossy encryption was originally studied as a means of achieving e cient and composable oblivious transfer. Also, data compression can speed up an encryption process, and a decryption process will produce corresponding plaintexts.
An image can be compressed by reducing its colour depth. These techniques are used to reduce data size for storing, handling, and transmitting content. The original file cannot be recovered from the compressed version as the removed data is lost. Introduction to data compression, third edition khalidsayood understanding digital libraries, second edition. Efficient compression and encryption for digital data. In information technology, lossy compression or irreversible compression is the class of data encoding methods that uses inexact approximations and partial data discarding to represent the content. Data compression can be defined as the coding of data to minimize its representation. Data compression or source coding is the process of creating binary representations of data which require less storage space than the original data 7. Pdf lossy compress is most commonly used when the user needs to compress multimedia data that consists of video, audio and still images. A read is counted each time someone views a publication summary such as the title, abstract, and list of authors, clicks on a figure, or views or downloads the fulltext. The theoretical background of the data compression techniques is strong and well established. They claim that in as many as 70% of the cases studied, implementing cryptography and then compression is more efficient, because.