Secure Electronic Transaction (SET) is a security protocol for electronic payments.

The Data Encryption Standard (DES)is a Symmetric key data encryption method.

A digital signature is a mechanism that is used to verify that a particular digital document, message or transaction is authentic.

Non-repudiation: Repudiation refers to any act of relinquishing responsibility for a message. Non-repudiation ensures that the signer who digitally signed the document cannot deny having signed it. The digitally signed documents strengthen its recipient integrity claims. Therefore, the recipient can strongly insist on the signature of the sender so as not to be easily denied at a later time.

Typopiracy is a variant of Cyber Squatting. Some fake websites try to take advantage of users common typographical errors in typing a website address and direct users to a different website. Such people try to take advantage of some popular websites to generate accidental traffic for their websites. e.g. www.goggle.com, www.facebook.com

Phil Zimmermann developed PGP in 1991. It is a decentralized encryption program that provides cryptographic privacy and authentication for data communication. PGP encryption uses a serial combination of Hashing, data compresion, symmetric key cryptography and asymmetric key cryptography and works on the concept of "web of Trust" It is also called "Pretty Good Privacy".

(i) The certificate authority maintains a database of public keys called repository so that it can verify the user with digital signatures.
(ii) Expired certificates are usually deleted from the database by the certificate authority.

1. The most common cryptographic protocol is Secure Sockets Layers (SSL). SSL is a hybrid encryption protocol for securing transactions over the internet. The SSL standard was developed by Netscape in collaboration with Mastercard, Bank of America, MCI and silicon graphics.
2. Today, all browsers in the market support SSL, and most of the secure communication are proceeded through this protocol. SSL works completely hidden for the users, who does not have to intervene in the protocol.
3. The only thing the user has to do is make sure on URL starts with https://instead of http:// where "s" obviously means secured.
4. SSL was renamed as TLS (Transport Layer Security) in 2001.

Encryption technology is an effective information security protection. It is defined as converting a plaintext into meaningless ciphertext using encryption algorithm thus ensuring the confidentiality of the data. The encryption or decryption process use a key to encrypt or decrypt the data. At present two encryption technologies are widely used. They are symmetric key encryption system and an asymmetric key encryption system. Thre figure below shows the Data Encryption and Decryption process:

Confidentiality

Confidentiality

Cyber Squatting

d) (A) is false and (R) is true

d) (A) is false and (R) is true.