Follow us Youtube Rss Twitter Facebook

العودة   منتدى افهم كمبيوتر > >

دورات و دروس تعليمية | Computer courses دروس و دوارات متنوعة في مجالات مختلفه

إضافة رد
أدوات الموضوع انواع عرض الموضوع
قديم 02-09-2012 المشاركه رقم : 1
مروان عاطف جابر

الصورة الرمزية مروان عاطف جابر

تاريخ التسجيل : Nov 2011
رقم العضوية : 1833
الإقامة : الاسكندرية
المشاركات : 5
مروان عاطف جابر will become famous soon enough

مروان عاطف جابر غير متواجد حالياً

W (2) What Is The Encryption Systems For Letters and Numbers ?

Encryption Systems for Letters and Number
This is My Collage Report About Encryption Systems For Letters and Numbers
authorship : Marwan Atef Gaber
Search index
• Summary
• In General
• What is the science of encryption?
• Binary system 0&1
• ASCII Code
• ANSI Code

• References
In General

What is Unicode, ASCII, and ANSI?
Unicode is a map, a chart of (what will one day be) all of the characters, letters, symbols, punctuation marks, etc. necessary for writing all of the world’s languages past and present.
If you have ever tried typing in a non-English language using the Roman alphabet (e.g. French) you may recall memorising a set of numbers that signify accented letters. So that alt-130 is é, and alt-160 is á. This numbering system is called ASCII, which has been with us since the DOS days. A newer mapping commonly called ANSI, expanded on ASCII giving us capital versions of the accented letters Á É, and a few extra glyphs like Icelandic ð and þ. ANSI allows one to write in any of the major western European languages (but not all: the Welsh letters ŵ ŷ are not available on the ANSI mapping).
ASCII and ANSI are pretty good as long as you are western European. These two mappings are extremely limited in that they may only code (i.e. assign a number to) 256 letters, so that there is no space to include other glyphs from other languages.
Unicode fixes this problem, by providing enough space for over a million different symbols. Like the above two systems, each character is given a number, so that Russian Я is 042F, and the Korean won symbol ₩ is 20A9. (Note that all Unicode numbers are Hexadecimal, meaning that one counts by 16’s not 10’s, not a problem as users really don’t need to know the mapping numbers anyway.) So, although not yet totally comprehensive, Unicode covers most of the world’s writing systems. Most importantly, the mapping is consistent, so that any user anywhere on any computer has the same encoding as everyone else, no matter what font is being used.
Which computers can use Unicode?
As far as Windows goes, only NT, 2000, and XP take advantage of Unicode. In these operating systems, it is possible to read, type, print, etc. using Unicode mappings, providing of course that you have the appropriate font and keyboard drivers. With the other Windows, (95, 98, me), typing in Unicode is not really possible (Alan Wood has a list of which software are Unicode friendly, along with much much more about Unicode). The 95, 98, me Windows versions do allow users to view Unicode though, with up-to-date Netscape or Explorer versions. Unicode also works on recent Mac operating systems.
What doesn’t Unicode do?
Remember, Unicode is not a font, but basically a coding system, where symbols are given numbers. Most fonts only carry a fraction of the full Unicode inventory, so that the fonts on this site have glyphs for Syllabics, but not for Chinese or Malayalam. So if you try to read a Chinese site without a Unicode font with Chinese included, it’s not going to work.
• Unicode does not have different code numbers for different versions of the same letter. For example, the regular g and the italic g have the same number (0067). This makes sense because a single letter may have many different shapes, depending on size, language, style, artistic design, and so on. (OpenType fonts handle different styles very well)
• Unicode is inconsistent with regards to which symbols get unique codes, and which do not. So that all of the accented letters of the European languages have their own code (Ő is 0150), but Native American symbols, like Guaraní g̃ have to be made up from two codes, 0067 (g) and 0303 (combining ~) or Dene Ų̀. Notice that the ~ and ` accents may not be placed very well, and depending on the font, makes for an unattractive look (OpenType fonts can fix this).

What is the science of encryption?
The science of encryption systems existed since ancient times . Hieroglyphic language is an encryption system for us comparing to other languages like Arabic , English ,…..etc. But our encryption in this search is for computers. The computer have an encryption system called binary code it only uses (0 & 1), this computer can`t understand any language or non-binary encryption code .

The encryption code is a very important thing in our lives that we can use it in (the Internet, e-commerce, mobile telephones, wireless microphones, wireless intercom systems, Bluetooth devices , bank automatic teller machines and more )
Despite all this amazing progress we have some problems against encryptions codes we use it now such as (The digital signature)

Binary numeral system
binary numeral system is the system of counting based on 2 numbers, Its used to represent numeric values using two symbols, usually are 0 and 1 .You can also use any symbols or two cases such as 0 , 1 and error .Or on / off amortization. Because of these we use it in directly implementation of logic gates and digital electronics , the virtually algorithm used in all modern computers.

The relation between Binary numeral and Decimal numbers
Decimal numbers
Depends on the fields, each field contains 10 potential from 0 to 9 there is a basis to determine the fields Individual - dozens - hundreds – thousands
Example : 567 mean >> 500 + 60 + 7
Mean >> 7*10+ 6*10¹ +5*10²
Binary numeral
Depends on 2 fields each field contains 2 potential 0 or 1
The first field equals the number * 02 ( 1 )
And the second field equals the number * 12 (2)
The third field equals the number * 22 (4)
that means number 10 equals
0*02 + 1 * 12 = 0*1 + 1*2 = 0 + 2 = 2
Examples :
Number 101 (Binary numeral)
Equals in Decimal numbers
1 * 02 + 0 * 12 + 1 * 22 = 1*1 + 0*2 + 1*4 = 1 + 0 + 4 = 5
Number 100101 (Binary numeral)
Equals in Decimal numbers
1*02 = 1*1 =1
1*12 = 0*2 = 0
1*22 = 1*4 =4
1*32 =0*8 =0
1*42 =0*16 =0
1*52 =1*32 =32
1 + 0 + 4 + 0 +0 + 32 = 37


In a very simplified method tables depend on>>>>> tables contain symmetries .For example each character is matched by a code and those tables are saved in the computing devices such as mobiles , laptops and ipads.
ASCII is an encryption system of 7 decided by seven binary digits using the rule (a value between 0 and 127) to represent letters and symbols. At the time, who suggested the system ASCII, many of the devices to deal with groups of eight decided (known as bytes or Octet) smallest unit information; Commonly used to decide the eighth as the parity bit for the purposes of ensuring that the error checking on communication lines and for other purposes related to the purpose of the devices used.
Known as ASCII relationship between a symbol or a particular character and arrangement of bits; addition to booking a set of control codes to the data stored in the form of lines, and does not support ASCII how to describe the structure or format text within a Document particular, it falls within the scope of other systems such as Markup Languages.
To know what is ASCII tables go there
To convert text to binary ( ASCII )

Information about Unicode >>
Fundamentally, computers just deal with numbers. They store letters and other characters by assigning a number for each one. Before Unicode was invented, there were hundreds of different encoding systems for assigning these numbers. No single encoding could contain enough characters: for example, the European Union alone requires several different encodings to cover all its languages. Even for a single language like English no single encoding was adequate for all the letters, punctuation, and technical symbols in common use.
These encoding systems also conflict with one another. That is, two encodings can use the same number for two different characters, or use different numbers for the same character. Any given computer (especially servers) needs to support many different encodings; yet whenever data is passed between different encodings or platforms, that data always runs the risk of corruption.
Unicode is changing all that!
Unicode provides a unique number for every character, no matter what the platform, no matter what the program, no matter what the language. The Unicode Standard has been adopted by such industry leaders as Apple, HP, IBM, Just Systems, Microsoft, Oracle, SAP, Sun, Sybase, Unisys and many others. Unicode is required by modern standards such as XML, Java, ECMAScript (JavaScript), LDAP, CORBA 3.0, WML, etc., and is the official way to implement ISO/IEC 10646. It is supported in many operating systems, all modern browsers, and many other products. The emergence of the Unicode Standard, and the availability of tools supporting it, are among the most significant recent global software technology trends.
Incorporating Unicode into client-server or multi-tiered applications and websites offers significant cost savings over the use of legacy character sets. Unicode enables a single software product or a single website to be targeted across multiple platforms, languages and countries without re-engineering. It allows data to be transported through many different systems without corruption.
About the Unicode Consortium
The Unicode Consortium is a non-profit organization founded to develop, extend and promote use of the Unicode Standard, which specifies the representation of text in modern software products and standards. The membership of the consortium represents a broad spectrum of corporations and organizations in the computer and information processing industry. The consortium is supported financially solely through membership dues. Membership in the Unicode Consortium is open to organizations and individuals anywhere in the world who support the Unicode Standard and wish to assist in its extension and implementation.


رد مع اقتباس
قديم 02-10-2012 المشاركه رقم : 2
amr selim

الصورة الرمزية amr selim

تاريخ التسجيل : Jun 2010
رقم العضوية : 3
الإقامة : Egypt
المشاركات : 4,990
amr selim تم تعطيل التقييم

amr selim غير متواجد حالياً

افتراضي رد: What Is The Encryption Systems For Letters and Numbers ?

الله يبارك فيك معلومات قسمه عن انظمة التشفير لحروف سلمت يداك لي رجعه للاستفاضة فيه ان شاء الله
بس ياريت يا حبيب تراعي التنسيق لو سمحت


Efham Computer

رد مع اقتباس
إضافة رد

الكلمات الدلالية (Tags)
encryption , letters , numbers , systems

الموضوع الحالى: What Is The Encryption Systems For Letters and Numbers ?    -||-    القسم الخاص بالموضوع: دورات و دروس تعليمية | Computer courses    -||-    المصدر: منتدى افهم كمبيوتر    -||-    منتدى افهم كمبيوتر
أدوات الموضوع
انواع عرض الموضوع

تعليمات المشاركة
لا تستطيع إضافة مواضيع جديدة
لا تستطيع الرد على المواضيع
لا تستطيع إرفاق ملفات
لا تستطيع تعديل مشاركاتك

BB code is متاحة
كود [IMG] متاحة
كود HTML معطلة

الانتقال السريع

بيان الخصوصية - Privacy-Policy

الساعة الآن 05:50 PM.