A message that has been sent encrypted using the public key of the receiver can be generated by anyone, but can only
be read by the receiver. This is one basis of confidentiality. In theory, a message that has been encrypted twice, first
by the sender’s secret key, and second by the receiver’s public key, achieves both authentication and confidentiality
objectives, but it is not commonly used because it could generate performance issues.
Elliptical Curve Cryptography
Although public key cryptography ensures message security, the long keys and mathematical problems it uses tend to
be inefficient. A variant and more efficient form of public key cryptography is elliptical curve cryptography (ECC),
which is gaining prominence as a method for increasing security while using minimum resources. It is believed that
ECC demands less computational power and therefore offers more security per bit. For example, an ECC with a
160-bit key offers the same security as an RSA-based system with a 1,024-bit key.
ECC works well on networked computers requiring strong cryptography. However, it has some limitations such as
bandwidth and processing power.
Quantum Cryptography
Quantum cryptography is the next generation of cryptography that may solve some of the existing problems
associated with current cryptographic systems, specifically the random generation and secure distribution of
symmetric cryptographic keys. It is based on a practical application of the characteristics of the smallest “grains” of
light (photons) and the physical laws governing their generation, propagation and detection. Initial commercial usage
has already started now that the laboratory research phase has been completed.
Advanced Encryption Standard
AES has replaced the DES as the cryptographic algorithm standard. It originated in 1997, when NIST announced the
initiation of the AES development effort and made a formal call for algorithms. In October 2000, NIST announced
that it had selected Rijndael as the algorithm for the AES. This algorithm was developed by Dr. Joan Daemen and
Dr. Vincent Rijmen.