SCRAMBLER AND DESCRAMBLER PDF

Low cost highly secure image scrambler and descrambler. Abstract: Multimedia data security is very important for multimedia commerce on the Internet such as. time data multicast. An striking solution for encrypting data with adequate message security at low cost is the use of Scrambler/Descrambler. Scramblers are. Scramblers and descramblers in Galois and Fibonacci based LFSR configurations.


SCRAMBLER AND DESCRAMBLER PDF

Author: Vivian Langworth
Country: Germany
Language: English
Genre: Education
Published: 15 February 2014
Pages: 621
PDF File Size: 27.46 Mb
ePub File Size: 11.76 Mb
ISBN: 727-2-44302-983-5
Downloads: 15816
Price: Free
Uploader: Vivian Langworth

SCRAMBLER AND DESCRAMBLER PDF


Using modern public-key systemsthese "scramblers" are much more secure than their earlier analog counterparts. Only these types of systems are considered secure enough for sensitive data.

Solved: What is the usage of Scrambler/Descrambler feature - Community Forums

Voice inversion scrambling can be as simple as inverting the frequency bands around a static point to various complex methods of changing the inversion point randomly and in real time and using multiple bands. The "scramblers" used in cable television are designed to prevent casual signal theft, not scrambler and descrambler provide any real security.

SCRAMBLER AND DESCRAMBLER PDF

Early versions of these devices simply "inverted" one important component of the TV signal, re-inverting it at the client end for display. Later devices were only slightly more complex, filtering out that component entirely and scrambler and descrambler adding it by examining other portions of the signal.

Scrambler/Descrambler in standard - MATLAB Answers - MATLAB Central

In both cases the scrambler and descrambler could be easily built by any reasonably knowledgeable hobbyist. Electronic kits for scrambling and descrambling are available from hobbyist suppliers.

Scanner enthusiasts often use them to listen in to scrambled communications at car races and some public-service transmissions.

SCRAMBLER AND DESCRAMBLER PDF

It is also common in FRS radios. This is an easy way to learn about scrambling. The term "scrambling" is sometimes incorrectly used when scrambler and descrambler is meant. Descramble[ edit ] Descramble in cable television context is the act of taking a scrambled or encrypted video signal that has been provided by a cable television company for premium television services, processed by a scrambler and then supplied over a coaxial cable and delivered to the household where a set-top box reprocesses the signal, thus descrambling it and making it available scrambler and descrambler viewing on the television set.

It is a further object of scrambler and descrambler present invention to cause a permutation scrambler and descrambler the data in such a way that a series of continuous ones or zeros is transformed into a pseudo random sequence.

It is yet another object of the invention to provide a scrambler that does not propagate and multiply occasional single bit errors of an otherwise good data signal into multiple bit errors that may disrupt the flow of data.

It is still a further object of the invention to provide a descrambler which is located at the RF destination for reconstructing the permuted data back into the original data sequence. The foregoing objects and advantages scrambler and descrambler the invention are illustrative of those which can be achieved by the present invention and are not intended to be exhaustive or limiting of the possible advantages which can be realized.

Some simplifications and omissions may be made in the following summary, which is intended to highlight and introduce some aspects scrambler and descrambler the present invention, but not to limit its scope. Detailed descriptions of a preferred exemplary embodiment adequate to allow those of ordinary skill in the art to make and use the inventive concepts will follow in later sections.

Select a Web Site

In one embodiment of the present invention, a scrambler system provides for the detection and separation of synchronization signals from data signals, and further provides an exclusive OR operation to a pseudo random number sequence and the desired data stream prior to its modulation and transmission.

At the receiving end, the identical pseudo random sequence is exclusive OR'ed with the demodulated data, scrambler and descrambler the data to be restored to its original form. Thus, the effect of a continuous stream of ones or zeros is eliminated by the pseudo random sequence.

Referring to the drawings, wherein like numerals refer to like components, there is illustrated in FIG. The circuit 1 includes, generally, a shift register circuit 2, a frame locking circuit 4, an adder 6, a flip-flop 8, pseudo-random number generator 10, an exclusive OR gate 12, and flip-flop 14 A clock scrambler and descrambler signal is applied to some, but not all, components of the scrambler 1 to provide timing pulses, as is commonly practiced in the art.

Data transmitted to the scrambler 1 is preferably formatted into frames that consist of a pre-selected multibit synchronization "sync" character followed by bits of data.

Scrambler - Wikipedia

Scrambler and descrambler shift register 2 preferably comprises a chain of eight flip-flops sequentially connected together in a circuit, but it is not so limited. As is apparent to one skilled in the art, the particular type of shift register employed in the present invention is not limited to a sequential chain of flip-flops, for the purpose of shifting stored data.

Accordingly, other shift registers known in the art may be used to accomplish a similar result, without departing from the scope of the invention.

SCRAMBLER AND DESCRAMBLER PDF

The shift register 2 contains single-bit parallel outputs QA through QH, in which QH is preferably the output connection of the data stream after it is sequentially shifted through the eight flip-flops.

The outputs of NOR gates 20, 22, 24 and 26 are then connected to the input of adder 6. Scrambler and descrambler output QH of shift register 2 is not connected to adder 6, but rather it is connected to the input of eclusive-OR gate The output of NOR gate 34 is applied to the load input of each of three 4-bit up-down counters 36, 38 and scrambler and descrambler that are sequentially linked together.

The 4-bit counters preferably are the type that are well known and commercially available in the industry, but the invention is not so limited in that any suitable device for providing a counter function may be used in the present invention.