Survey on Perfectly Reliable and Secure Message Transmission.

Date of Submission

December 2011

Date of Award

Winter 12-12-2012

Institute Name (Publisher)

Indian Statistical Institute

Document Type

Master's Dissertation

Degree Name

Master of Technology

Subject Name

Computer Science


Theoretical Statistics and Mathematics Unit (TSMU-Kolkata)


Barua, Rana (TSMU-Kolkata; ISI)

Abstract (Summary of the Work)

In the study of the cryptosystems, we are interested in that type of cryptosystems which provide perfect security against a computationally unbounded third party. When the sender S and the receiver R are connected by a single channel which can reveal information to a third party, it is not possible to design a cryptosystem which does not reveal any information about the message. This leads to a problem where the sender and the receiver are part of an unreliable, connected, distributed network. The distrust in the network is modeled by an entity called adversary, who has unbounded computing power and who can corrupt some of the nodes of the network (excluding S and R) in a variety of ways. S wants to send to R a message mS that consists of ` elements, where ` ≥ 1, selected uniformly from a finite field Zq. Our aim is to design a protocol, such that the receiver will recover the message correctly after communicating certain number of times with the sender. And the receiver should be able to recover the message in spite of the presence of the disrupting authority. The protocols which are able to do this is called perfectly reliable message transmission (PRMT) protpcol. Now, if the protocols are such that, the adversary does not get any information about the message, we call them as perfectly secure message transmission (PSMT) protpcol. Security against an adversary with infinite computing power is also known as non-cryptographic or information theoretic or Shannon security and this is the strongest notion of security.RMT and SMT problem can be studied in various network models and adversarial settings. We may use the following parameters to describe different settings/models for studying RMT/SMT: Type of Underlying Network (Undirected Graph, Directed Graph, Hypergraph), Type of Communication (Synchronous, Asynchronous, Adversary capacity (Threshold Static, Threshold Mobile, Nonthreshold Static, Non-threshold Mobile)Type of Faults (Fail-stop, Passive, Byzantine, Mixed).Irrespective of the settings in which RMT/SMT is studied, we have to deal with some common issues. First one is that, we have to find out the necessary and sufficient structural conditions to be satisfied by the underlying network for the existence of any RMT/SMT protocol, tolerating a given type of adversary. Now, if a protocol exists in a network our aim will be to find an efficient and optimal protocol. In this dissertation, we look into the above issues in several network models and adversarial settings. More specifically, we survey some well known SMT schemes and study their properties.


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Creative Commons License

Creative Commons Attribution 4.0 International License
This work is licensed under a Creative Commons Attribution 4.0 International License.


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