Abstract:
This paper presents data transfer system
between two users using the asymmetric-key
cryptography. Asymmetric-key cryptography or
public-key cryptography is cryptography in which
a pair of keys is used to encrypt and decrypt a
message so that it arrives securely. A message can
be encrypted with the receiver’s public key and
decrypted with the receiver’s private key to
provide security. A higher level of security can be
achieved by placing controlled trusted center as a
directory of public keys. Controlled Trusted
Center keeps the public key of the registered users
in its directoryand responsible to respond to any
inquiry about the public key. The public-key
announcements can include a timestamp and be
signed by an authority to prevent interception and
modification of the response. A signature is a
technique for non-repudiation based on the public
key cryptography. RSA digital signature and SHA-
1 hash function are applied to provide integrity
and authentication during the public key
distribution. RSA encryption algorithm is also
used for encryption in this secure message
transfer system. RSA is two algorithms: one for
asymmetric encryption and one for signatures.
