This is realized through digital signing of the SMS. The advantage of asymmetric encryption is in its
functionality. It provides security in a wide range of applications that cannot be solved using only symmetric
techniques. The issue with asymmetric encryption is that it is slower than symmetric encryption because they
require more computational processing power and which makes it impractical when trying to encrypt large
amounts of data. But here, small data is to be encrypted like SMS and system don’t want to send the shared secret
key from one end to another of the peer entities, so it is suitable to choose asymmetric encryption for the SMS.
This scheme supports some of the most used digital signature schemes (i.e. DSA, and ECDSA) and public-key
based cryptosystems (i.e. RSA and El-gamal). A modified version of RSA is proposed with OAEP (Optimal
asymmetric encryption padding) which will provide more security to the algorithm. Apart from these schemes,
some message digest algorithms based on hash function or MAC function will also be analyzed and optimal
solution based on these all algorithms will be implemented which ensure the proper security of SMS.