Random Network Coding in Real-Time Application

There is no re-transmission time for the real time streaming. So some of the packets or symbols with less information content can be discarded when received with error. There could be another issues of secured transmission.

This security issues can be addressed using Random Network Coding with triangular transformation matrix. Packets of lower information content or lower priorities can be transmitted and decoded with the prior knowledge of higher information content symbols or packets. Extraction of information is not possible when higher priority symbol has error.

New Perspective over Information Flow

Information Theory

Information Theory has been introduced to represent source symbols randomly generated with encoding symbols accordingly how much information is carrying by the symbols. This equivalent representation minimizes the network loads by reducing number of flowing encoding symbols over the network and making the network non-degenerated. Random nature of a source or sender carries information and so there is existence of information theory. 

Network Coding Theory

There is another philosophy of generating a function which represents lots of information symbols with lesser number of information symbols in the same base field and the philosophy is Network Coding Theory. For digital representation of symbols, Network Coding Theory evaluate a functions which represents lots of information carrying binary base field symbols (bit) to lesser number of bits, encoding, which has capability of generating all information bits from the functions evaluated and the algorithm is decoding. 

Information Theory and Secure Network Codes

Information theory deals with the theory to generate replica of symbols at source nodes to sink nodes which defines the efficiency of the communication system.

Network coding theory deals with reliable transmission of symbol to sink nodes with reduced contamination and avoiding malicious tempering, spoofing and jamming by adversaries in the network.

Three approaches of security:

1. computational security 
2. physical security 
3. information theoretic security 

Secure Network coding deals with information theoretic security with no information gained by the wiretapper about the transmitting messages out of eavesdropped message. 

Shannon Ciphar system models sending of secrete key to destination through private channel without access of adversaries and message to sink node through the public channel, where without knowing secret key, adversaries gain no information about the source message. 

Another wiretap model sends secret message to sink nodes after encoding to code-word via noiseless channel and message symbol via public channels which could be tapped by adversaries.

Secret sharing model shares random secret symbols among the legitimate users and coded user message will be decoded with the secret symbol received by legitimate users and illegitimate user get no knowledge about the message transmitted over public channel without knowledge of secret message.