Motion compensated permutation-based video encryption

• Autor(a) principal: SILVA, Caio César Sabino
• Data de Publicação: 2015
• Tipo de documento: Dissertação
• Idioma: eng
• Título da fonte: Repositório Institucional da UFPE
• Texto Completo: https://repositorio.ufpe.br/handle/123456789/23821
• topic: Ciência da computação; Segurança de dados multimídia

In the context of multimedia applications security, digital video encryption techniques have been developed to assure the confidentiality of information contained in such media type. Compression and encryption used to be considered as opposite in terms of exploring the data’s entropy, however in the last decades there was an increase of data volume operated by video encryption applications which demanded improvements on data compressibility in video encryption. In this sense, many techniques have been developed as entropy coding providing both encryption and compression simultaneously. An existing cryptographic scheme, introduced by Socek et al., is based on permutation transformations and applies encryption prior to the compression stage. The encryption applied by this technique may not be as safe as a conventional encryption technique, but its security is still considered acceptable for most video applications. It can improve the original data’s spatial correlation in case the consecutive frames are similar, making it possibly even more compressible than the original video. However the original cryptographic scheme was designed to explore only the spatial correlation inside every frame, but codecs can also explore non-trivial temporal correlation. Also the improvements on the data’s spatial correlation coming from the permutation transformations are highly based on the natural temporal correlation in the video. Hence its performance is extremely associated to the amount of motion in the video. The work developed in this dissertation aims to extend this cryptographic scheme, including motion compensation concepts to the permutation based transformations used in the video encryption technique to improve its performance and make it more resilient to high motion videos.