  Cryptography is the science of encrypting the information so that it is
rendered unreadable for an intruder. Cryptographic techniques are of utmost
importance in today's world as the information to be sent might be of
invaluable importance to both the sender and the receiver. Various
cryptographic techniques ensure that even if an intruder intercepts the sent
information, he is not able to decipher it thus render ending it useless for
the intruder. Cryptography can be grouped into two types, that is Symmetric key
cryptography and Asymmetric key cryptography. Symmetric key cryptography uses
the same key for encryption as well as decryption thus making it faster
compared to Asymmetric Key cryptography which uses different keys for
encryption and decryption. Generation of dynamic keys for Symmetric key
cryptography is an interesting field and in this we have tapped this field so
as to generate dynamic keys for symmetric key cryptography. In this work, we
have devised an algorithm for generating dynamic keys for sending messages over
a communication channel and also solving key refreshment problem.
