This talk describes the project Design of a Block Cipher which was sponsored by the NCETIS, at IIT Bombay. The objective of the project was to develop a family of Block Cipher algorithms for use by Indian Govt. agencies. As per the policy followed by Govt. agencies in cipher algorithms it is mandatory that the algorithm should not be a published one. It is notoriously difficult and time consuming to design a completely new algorithm which is secure. On the other hand, Govt. agencies require a rapid production of such secure algorithms. Hence in this project it was decided to first create a family of designs which will be able to enhance the security of known and already in use algorithms. With such a motivation we first see a new method of variation of algorithms by key extension which makes a known algorithm more secure than before. Next a methodology for randomization of a cipher algorithm was utilized to produce a new block cipher family. The architecture of this new family of algorithms was developed and analyzed and is ready for Govt. agencies to adopt if any such agency is interested.