Abstract:
In modern communication age, security of electronic message transaction is the demand of
time. It is most essential in various aspects. Currently a large amount of sensitive data is
transmitted over the open network or internet or other communication channels on a daily basis.
Without strong security, we cannot protect these sensitive information from malicious attacks.
Currently, it is main concern to impose additional security services to the communicating
message, communication channel and communicating participants. For this, a better approach
for electronic message transaction system has been developed using Python programming
language. It performs electronic message transactions with all the fundamental security
requirements, which are confidentiality, integrity, authentication and non-repudiation for both
communicating message and communicating participants. To do this, simple cryptographic
encryption and decryption techniques are used to the communicating messages. At first
message is encrypts with the private key of sender PRa and the output is again encrypts with a
shared secret key K1 that generates cipherext, which is again encrypts with another shared
secret key K2 that generates a code that serves as message authenticator known as MAC, which
is concatenates with the ciphertext and again encrypts them with shared secret key K1 that
builds the new cphertext, which is again encrypts with the receiver’s public key PUb to produce
final ciphertext that is to be send to the intendent recipient. In the receiving end, to retrieve the
message, receiver at first decrypts the received information with his private key PRb and again
decrypts with the shared secret key K1 that gives the ciphertext and MAC of the ciphertext, and
then only decrypts the MAC to generate a new ciphertext′ and compare the new ciphertext′
with the received ciphertext that ensures the ciphertext authentication as well as message
authentication; if ciphertexts are found same, then decrypts the ciphertext with shared secret
key K1 and again decrypts with the sender public key PUa and retrieve the message; otherwise
discard it. This technique can be applied anywhere of electronic communications in a secure
fashion.
