Internet Foundations 3

Spyware (or adware) is a software application that a secretly placed on a user's system to gather information and relay it to outside parties, usually for advertising purposes.

MIME types used to identify a document type and the application required to open it.

Encryption applications dramatically reduce the risk of information theft by scrambling the information using mathematical algorithm. Encrypted data is referred to as ciphertext; unencrypted data is referred to as a plaintext.

Typosquatting refers to an unethical practice in which the perpetrator (i.e. typosquatter) capitalises on typing mistakes that users make when entering the URL of a Web site into a browser. When a Web user accidentally enters an incorrect Web site address, he or she may end up viewing an alternative Web site owned by a typosquatter. Web site owners can try to avoid falling victim to a typosquatter by purchasing domain names that are similar to their actual domain name.

Explanation/Reference: Google determines a site's popularity according to the number of other sites that link to it. Like other sites, Google's Web search engine is designed to rank the relevance of a particular site according to the keywords entered by the user.

Search engines sometimes yield unexpected results such as an error page, an alternative search engine or an advertisement instead of the topic for which you were searching. Error pages most commonly occur when you enter erroneous search criteria, click a dead link or try to access a busy server.

The different between a worm and a virus is that a worm has the ability to replicate itself automatically, whereas a virus requires user action.

Symmetric encryption (also called symmetric-key encryption or private-key encryption) is an encryption method in which same key is used to encrypt and decrypt a message.

Asymmetric encryption (also called asymmetric-key encryption or public-key encryption) refers to an encryption method in which two keys are used to encrypt and decrypt a message: a private and a public key. The public key is known to all sending and receiving parties involved in the communication.

Digital signatures can be used to enforce non-repudiation, which is the ability to prove that a transaction occurred. Sending data with a digital signature proves that the message was both sent and received.

The results will contain one keyword or the other or both.

Hash encryption provides data integrity because, even though encrypted data is not decrypted, you can verify whether the data was altered after encryption. Hash encryption is useful for protecting passwords from disclosure.

A static index/site map enables users to manually search information portals to locate indexed information.

An information portal differs from a search engine in that an information portal will only index Web sites that are submitted manually. Information portals do not use spider programs to seek out Web sites. Thus, if you do not manually submit your site's address to the information portal, it will never know about or index your site, and never list your site in search results.