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URL Shortener
URL shortening is a technique on the World Wide Web in which a Uniform Resource Locator (URL) may be made substantially shorter and still direct to the required page. This is achieved by using a redirect which links to the web page that has a long URL. For example, the URL "" can be shortened to "", and the URL "" can be shortened to "". Often the redirect domain name is shorter than the original one. A friendly URL may be desired for messaging technologies that limit the number of characters in a message (for example SMS), for reducing the amount of typing required if the reader is copying a URL from a print source, for making it easier for a person to remember, or for the intention of a permalink. In November 2009, the shortened links of the URL shortening service Bitly were accessed 2.1 billion times. Other uses of URL shortening are to "beautify" a link, track clicks, or disguise the underlying address. This is because the URL shortener can redirect to just about any web ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
TinyURL
TinyURL is a URL shortening web service, which provides short aliases for redirection of long URLs. Kevin Gilbertson, a web developer, launched the service in January 2002 as a way to post links in newsgroup postings which frequently had long, cumbersome addresses. TinyURL was the first notable URL shortening service and is one of the oldest still currently operating. Service The TinyURL homepage includes a form which is used to submit a long URL for shortening. For each URL entered, the server adds a new alias in its hashed database and returns a short URL. According to the website, the shortened URLs will never expire. TinyURL offers an API which allows applications to automatically create short URLs. Short URL aliases are seen as useful because they are easier to write down, remember or distribute. They also fit in text boxes with a limited number of characters allowed. Some examples of limited text boxes are IRC channel topics, email signatures, microblogs (such as Twitt ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Internet Bot
An Internet bot, web robot, robot or simply bot, is a software application that runs automated tasks (scripts) over the Internet, usually with the intent to imitate human activity on the Internet, such as messaging, on a large scale. An Internet bot plays the client role in a client–server model whereas the server role is usually played by web servers. Internet bots are able to perform tasks, that are simple and repetitive, much faster than a person could ever do. The most extensive use of bots is for web crawling, in which an automated script fetches, analyzes and files information from web servers. More than half of all web traffic is generated by bots. Efforts by web servers to restrict bots vary. Some servers have a robots.txt file that contains the rules governing bot behavior on that server. Any bot that does not follow the rules could, in theory, be denied access to or removed from the affected website. If the posted text file has no associated program/software/app, then ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Web Crawlers
A Web crawler, sometimes called a spider or spiderbot and often shortened to crawler, is an Internet bot that systematically browses the World Wide Web and that is typically operated by search engines for the purpose of Web indexing (''web spidering''). Web search engines and some other websites use Web crawling or spidering software to update their web content or indices of other sites' web content. Web crawlers copy pages for processing by a search engine, which indexes the downloaded pages so that users can search more efficiently. Crawlers consume resources on visited systems and often visit sites unprompted. Issues of schedule, load, and "politeness" come into play when large collections of pages are accessed. Mechanisms exist for public sites not wishing to be crawled to make this known to the crawling agent. For example, including a robots.txt file can request bots to index only parts of a website, or nothing at all. The number of Internet pages is extremely large; even ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Address Munging
Address munging is the practice of disguising an e-mail address to prevent it from being automatically collected by unsolicited bulk e-mail providers. Address munging is intended to disguise an e-mail address in a way that prevents computer software from seeing the real address, or even any address at all, but still allows a human reader to reconstruct the original and contact the author: an email address such as, "no-one@example.com", becomes "no-one at example dot com", for instance. Any e-mail address posted in public is likely to be automatically collected by computer software used by bulk emailers (a process known as e-mail address scavenging). Addresses posted on webpages, Usenet or chat rooms are particularly vulnerable to this. Private e-mail sent between individuals is highly unlikely to be collected, but e-mail sent to a mailing list that is archived and made available via the web, or passed onto a Usenet news server and made public, may eventually be scanned and collec ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Session Hijacking
In computer science, session hijacking, sometimes also known as cookie hijacking, is the exploitation of a valid computer session—sometimes also called a ''session key''—to gain unauthorized access to information or services in a computer system. In particular, it is used to refer to the theft of a magic cookie used to authenticate a user to a remote server. It has particular relevance to web developers, as the HTTP cookies used to maintain a session on many websites can be easily stolen by an attacker using an intermediary computer or with access to the saved cookies on the victim's computer (see HTTP cookie theft). After successfully stealing appropriate session cookies an adversary might use thPass the Cookie techniqueto perform session hijacking. Cookie hijacking is commonly used against client authentication on the internet. Modern web browsers use cookie protection mechanisms to protect the web from being attacked. A popular method is using source-routed IP packets. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cross-site Scripting
Cross-site scripting (XSS) is a type of security vulnerability that can be found in some web applications. XSS attacks enable attackers to inject client-side scripts into web pages viewed by other users. A cross-site scripting vulnerability may be used by attackers to bypass access controls such as the same-origin policy. Cross-site scripting carried out on websites accounted for roughly 84% of all security vulnerabilities documented by Symantec up until 2007.During the second half of 2007, 11,253 site-specific cross-site vulnerabilities were documented by XSSed, compared to 2,134 "traditional" vulnerabilities documented by Symantec, in XSS effects vary in range from petty nuisance to significant security risk, depending on the sensitivity of the data handled by the vulnerable site and the nature of any security mitigation implemented by the site's owner network. Background Security on the web depends on a variety of mechanisms, including an underlying concept of trust know ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Random Number Generation
Random number generation is a process by which, often by means of a random number generator (RNG), a sequence of numbers or symbols that cannot be reasonably predicted better than by random chance is generated. This means that the particular outcome sequence will contain some patterns detectable in hindsight but unpredictable to foresight. True random number generators can be '' hardware random-number generators'' (HRNGS) that generate random numbers, wherein each generation is a function of the current value of a physical environment's attribute that is constantly changing in a manner that is practically impossible to model. This would be in contrast to so-called "random number generations" done by ''pseudorandom number generators'' (PRNGs) that generate numbers that only look random but are in fact pre-determined—these generations can be reproduced simply by knowing the state of the PRNG. Various applications of randomness have led to the development of several different metho ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hash Function
A hash function is any function that can be used to map data of arbitrary size to fixed-size values. The values returned by a hash function are called ''hash values'', ''hash codes'', ''digests'', or simply ''hashes''. The values are usually used to index a fixed-size table called a ''hash table''. Use of a hash function to index a hash table is called ''hashing'' or ''scatter storage addressing''. Hash functions and their associated hash tables are used in data storage and retrieval applications to access data in a small and nearly constant time per retrieval. They require an amount of storage space only fractionally greater than the total space required for the data or records themselves. Hashing is a computationally and storage space-efficient form of data access that avoids the non-constant access time of ordered and unordered lists and structured trees, and the often exponential storage requirements of direct access of state spaces of large or variable-length keys. Use of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Base 62
The base62 encoding scheme uses 62 characters. The characters consist of the capital letters A-Z, the lower case letters a-z and the numbers 0–9. It is a binary-to-text encoding schemes that represent binary data in an ASCII string format. 123456789ABCDEFGHJKLMNPQRSTUVWXYZabcdefghijkmnopqrstuvwxyz = 58 characters = base58 0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz = 62 characters = base62 0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz+/ = 64 characters = base64 In some fonts the 0 (zero), I (capital i), O (capital o) and l (lower case L) characters look the same, and thus are not used in the base58 encoding scheme. Base62 table : {, class="wikitable" style="text-align:center" , - !scope="col", Decimal !! scope="col" , Binary !!scope="col", Base62 , rowspan="17", !scope="col", Decimal !! scope="col" , Binary !!scope="col", Base62 , rowspan="17", !scope="col", Decimal !! scope="col" , Binary !!scope="col", Base62 , rowspan= ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Base 36
A senary () numeral system (also known as base-6, heximal, or seximal) has 6, six as its radix, base. It has been adopted independently by a small number of cultures. Like decimal, it is a semiprime, though it is unique as the product of the only two consecutive numbers that are both prime (2 and 3). As six is a superior highly composite number, many of the arguments made in favor of the duodecimal system also apply to senary. In turn, the logic, senary logic refers to an extension of Jan Łukasiewicz's and Stephen Cole Kleene's ternary logic systems adjusted to explain the logic of statistical tests and missing data patterns in sciences using empirical methods. Formal definition The standard Set (mathematics), set of digits in senary is given by \mathcal_6 = \lbrace 0, 1, 2, 3, 4, 5\rbrace, with a linear order 0 < 1 < 2 < 3 < 4 < 5. Let be the Kleene closure of , where is the operation of string concatena ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
HTTP Status
This is a list of Hypertext Transfer Protocol (HTTP) response status codes. Status codes are issued by a server in response to a client's request made to the server. It includes codes from IETF Request for Comments (RFCs), other specifications, and some additional codes used in some common applications of the HTTP. The first digit of the status code specifies one of five standard classes of responses. The optional message phrases shown are typical, but any human-readable alternative may be provided, or none at all. Unless otherwise stated, the status code is part of the HTTP standard (). The Internet Assigned Numbers Authority (IANA) maintains the official registry of HTTP status codes. All HTTP response status codes are separated into five classes or categories. The first digit of the status code defines the class of response, while the last two digits do not have any classifying or categorization role. There are five classes defined by the standard: * ''1xx informational re ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
