Security is becoming a trend of concern in current technology advancement. Growth and development of technology such as mobile, TV, Video, messaging, teleconferencing, webinars, telemedicine have influenced need to secure multimedia applications in daily life. Example increase in the application of Radio Frequency Identification (RFID) systems in ensuring surveillance as well as monitoring security in public, private and traffic has raised issues like violation of privacy, and security of targeted individuals (Secure age, 2016). Hackers and intruders have successfully trapped and phished information from such mediums and use it for to cause trouble to targeted individual. Development of a network of communications such as wireless and wired networks has facilitated easy access to video data, multimedia information, and sensitive telemedicine information (Pande, & Zambreno, 2013). Many systems of daily social life such as education, commerce, finance, defense, entertainments, health, and politics require maintaining privacy and security of sensitive data and information that should be protected before transmission and distribution.
Advancement in network ecosystem and rapid growth of big data in cloud computing technology has introduced digital protection and security to digital multimedia data users. In the provision of data and information security encryption and watermarking technologies have been introduced to facilitate better ways of dealing with multimedia data and information. Digital encryption guarantees a secure end to end communication and transfer of data and information. Digital watermarking guarantees privacy and copyright protection (NIST Transitions, 2011). New schemes and algorithms that guarantee encryption of data and information have been designed to promote encryption in mobile devices. The new design of algorithm and architectures for multimedia devices has been invented with tighter constraints on computational algorithm resources (NIST Transitions, 2011).
New Approaches Invented Include
It involves performing random permutation to video data using encryption schemes where image architecture remains same except that individual positions are shuffled. Scrambling techniques implements Digital Signal Processing (DSP) to perform orthogonal transformation of the initial image. The main transformation operations that ensure encryption include digital wavelet transformation and Hadamard transformation (Pande, & Zambreno, 2013). Scrambling encryption techniques are applied in analog and digital videos and real-time captured images such as surveillance clips, and camera feeds. Complex ciphers are ruled out due to delays and low speed of computation.
Other Common Techniques Applied Include
- Line Inversion Video Scrambling where entire signal scan or parts of scanned lines are inverted to encrypt an image.
- Sync suppression video scrambling involves eliminating some parts of a video clip through hiding sensitive parts. Horizontal and vertical lines get hidden or removed from the actual image.
- Line shuffle video scrambling this technique involves a reordering of signals on the screen.
- Cut and rotate video scrambling involves encrypting a video clip through cutting scan line into pieces and perform reassembling of the original pattern through permutation techniques.
The algorithm implements real-time transport protocol that encrypts packets using a series of steps. The technique utilizes AES (Advanced Encryption Standard). Algorithm allows incorporation of compliant format techniques such as Meyer and Gadegast (Pande, & Zambreno, 2013). The various levels of encryption can be implemented in selective encryption. The various steps include
- Algorithm 1: involves encrypting headers from specific points such as sequence layer o slice layer
- Algorithm 2: allow encryption of low-frequency DCT coefficient in selected frame blocks or entire block.
- Algorithm 3: allow encryption of frame blocks within P and B frames.
- Algorithm 4: allow encryption of different frames of parts of data and parts of images
Advantages of Digital Multimedia Encryption Technology
- Transcoding and joint scrambling compression allow flexibility to perform selective encryption that guarantees security to critical parts of data. It allows selection of different levels of security and transparency.
- Digital techniques such as multimedia algorithm allow less vulnerability to channel errors. It makes it easy to recover original image after distortion since transmitted image in encrypted mode is not affected by any errors in transformation.
- Digital multimedia encryption techniques guarantee a high level of compatibility to facilitate the transformation of domain signal processing. Scrambling involves changing spatial positions of individual images based on a particular frequency range. Watermarking techniques involve transforming domain tasks and may not require a cryptographic key to be supplied.
Disadvantages of Digital Multimedia Encryption Technology
- The level of multimedia security, as well as security guarantee, depend heavily on contents of the video. Complex video requires specialized, scrambling tools and equipment otherwise moist of encryptions may lead to distortion of the image or loss of integrity due to degraded quality.
- Algorithms that combine scrambling and compression methodologies may decrease video compression rate causing effects on random permutations that leads to the the probability distortion in Discrete Cosine Transform (DCT) algorithm (NIST Transitions, 2011).
- Digital algorithm techniques and schemes require a lot of space to accommodate graphical transformations as well as carrying error bits for comparing images. Screen reordering operations techniques implemented in some schemes cause a delay on output affecting processing time.
NIST Transitions (2011): Recommendation for Transitioning the Use of Cryptographic Algorithms and Key Lengths (SP800-131A) Retrieved from: http://nvlpubs.nist.gov/nistpubs/Legacy/SP/nistspecialpublication800-131a.pdf
Pande A., & Zambreno J. (2013). Embedded Multimedia Security Systems, USA: Springer-Verlag
Secure age (2016). E-News retrieved from: http://www.secureage.com/eNews_encryption.jsp