Which of the following cryptography demands less computational power and offers more security per bit?

December 23, 2021 by Admin

Which of the following cryptography demands less computational power and offers more security per bit?

  • Quantum cryptography
  • Elliptic Curve Cryptography (ECC)
  • Symmetric Key Cryptography
  • Asymmetric Key Cryptography

ECC demands less computational power and, therefore offers more security per bit. For example, an ECC with a 160-bit key offer the same security as an RSA based system with a 1024-bit key.

ECC is a variant and more efficient form of a public key cryptography (how tom manage more security out of minimum resources) gaining prominence is the ECC. ECC works well on a network computer requires strong cryptography but have some limitation such as bandwidth and processing power. This is even more important with devices such as smart cards, wireless phones and other mobile devices.

The following were incorrect answers:

Quantum Cryptography – Quantum cryptography is based on a practical application of the characteristics of the smallest “grain” of light, photons and on physical laws governing their generation, propagation and detection. Quantum cryptography is the next generation of cryptography that may solve some of the existing problem associated with current cryptographic systems, specifically the random generation and secure distribution of symmetric cryptographic keys. Initial commercial usage has already started now that the laboratory research phase has been completed.

Symmetric Encryption – Symmetric encryption is the oldest and best-known technique. A secret key, which can be a number, a word, or just a string of random letters, is applied to the text of a message to change the content in a particular way. This might be as simple as shifting each letter by a number of places in the alphabet. As long as both sender and recipient know the secret key, they can encrypt and decrypt all messages that use this key.

Asymmetric Encryption – The problem with secret keys is exchanging them over the Internet or a large network while preventing them from falling into the wrong hands. Anyone who knows the secret key can decrypt the message. One answer is asymmetric encryption, in which there are two related keys–a key pair. A public key is made freely available to anyone who might want to send you a message. A second, private key is kept secret, so that only you know it. Any message (text, binary files, or documents) that are encrypted by using the public key can only be decrypted by applying the same algorithm, but by using the matching private key. Any message that is encrypted by using the private key can only be decrypted by using the matching public key. This means that you do not have to worry about passing public keys over the Internet (the keys are supposed to be public). A problem with asymmetric encryption, however, is that it is slower than symmetric encryption. It requires far more processing power to both encrypt and decrypt the content of the message.


CISA review manual 2014 Page number 349 and 350

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