The Digital Revolution

The Digital Revolution
Chapter 16 Identification Numbers Chapter 17 Information Science

Identification Numbers
Chapter 16

Chapter 16: Identification Numbers Lesson Plan
Check Digits The ZIP Code Bar Codes Encoding Personal Data

Chapter 16: Identification Numbers Discussion
Think of examples of…. Identification Numbers Codes

Chapter 16: Identification Numbers Identification Numbers

Chapter 16: Identification Numbers Codes

Chapter 16: Identification Numbers Identification Numbers
Modern identification numbers serve at least two functions: The number should unambiguously identify the person or thing with which it is associated . The number should have a “self-checking” aspect. Code A group of symbols that represent information. Codes have been invented for storing, securing, and transmitting information.

Chapter 16: Identification Numbers Check Digits
A digit included in an identification number for the purpose of error detection. Mathematical calculations or schemes are used on the digits of the identification number to assign the check digit. Computers use the check digit to help detect typing errors during data entry to prevent and detect fraud and to find other errors.

Money Order Method U.S. Postal Service Money Order, American Express Travelers Check, Visa Travelers Check, Euro Bank Notes Procedure Add up all of the numbers, divide by 9, check digit is the remainder

Money Order Method Example Add up all of the numbers = 41 Divide by 9 41/9 9 x 4 = 36 Remainder 41 – 36 = 5 Check Digit is 5

Money Order Method Error Detection Will not detect mistake of replacing 0 with a 9, or vice versa. Will not detect transposition of digits

Airline Ticket Method Airline Tickets, UPS Packages, Avis and National Rental Cars Procedure Divide number by 7, check digit is the remainder

Airline Ticket Method Example Divide number by 7 /7 7 x = Remainder – = 3 Check Digit is 3

Airline Ticket Method Error Detection Will not detect substitution of 0 for a 7; 1 for an 8; 2 for a 9, or vice versa It will detect transpositions of adjacent digits except the pairs 0,7; 1,8; 2,9.

Universal Product Code (UPC) A bar code and identification number that are used on most retail items Example: Consider the number found on the bottom of a box of cornflakes. The first digit identifies a broad category of goods. The next five digits identify the manufacturer. The next five digits identify the product. The last is a check digit.

Universal Product Code (UPC) Method Weights Numbers in scheme used to multiply digits by UPC Code uses 3 & 1 Weights are chosen carefully so that up to100% of all single-digit errors and most other types of errors are found. Procedure Assign the weights 3, 1, 3, 1, 3, 1…to the identification number Multiply Add the products The Check Digit should bring the sum to a multiple of 10

Universal Product Code (UPC) Method Example Assign the weights 3, 1, 3, 1, 3, 1…. to the identification numbers (3)7 (1)9 (3)3 (1)5 (3)7 (1)3 (3)1 (1)7 (3)4 (1)6 (3)2 Multiply Add the products The Check Digit should bring to total to a multiple of 10 102 + _____ = 110

Universal Product Code (UPC) Method Error Detection Detects all single position errors Detects 89% of all other kinds of errors

Bank Identification Number The string of numbers at the bottom of a check mean 0710 Bank’s Federal Reserve District, office, and state 0001 Bank’s ID number Check digit Checking account number 0134 Customer’s check Procedure Assign the weights 7, 3, 9, 7, 3, 9…. to the identification numbers Multiply Add up the products Check Digit is the last number of the sum

Bank Identification Number Method Weights 7, 3, 9, 7, 3, 9…. Procedure Use First Chicago Bank Routing Number Assign the weights 7, 3, 9, 7, 3, 9…. to the identification numbers (7)0 (3)7 (9)1 (7)0 (3)0 (9)0 (7)0 (3)1 Multiply Add the products = 33 The check digit is the last digit of the sum The check digit is 3

Bank Identification Number Method Error Detection Detects all single position errors Detects all adjacent transposition errors Detects most other transposition errors

Codabar All major credit-card companies, many libraries, blood banks, photofinishing companies, South Dakota driver’s license department After the bank issues a card number, it adds an extra digit for error detection created by certain math calculations using a check digit scheme. This makes it difficult to create phony credit cards!

Codabar Procedure Add the digits in the odd positions (1, 3, 5, 7, 9, 11, 13, 15) Double the sum Count the number of digits odd positions (1, 3, 5, 7, 9, 11, 13, 15) that exceed 4 Add this to the total Add the remaining digits Check digit is number that brings the total number to a multiple of 10 (ends in zero)

Chapter 16: Identification Numbers Check Digits – Codabar
Bank intends to issue a card with the number What is the check digit? Add the digits in the odd positions (1, 3, 5, 7, 9, 11, 13, 15) = 25 Double the sum 25 x 2 = 50 Count the number of digits odd positions (1, 3, 5, 7, 9, 11, 13, 15) that exceed 4 Add this to the total = 52 Add the remaining digits = 68 Check digit is number that brings the total number to a multiple of 10 (ends in zero) 68 + ____ = Check Digit is 2

Codabar Error Detection Detects 100% of single-position errors Detects 98% of other common errors

International Standard Book Number (ISBN) A ten-digit identification number used on books throughout the world that contains a check digit for error detection. Our ISBN may become 13-digits soon, just like Europe (EAN) .

International Standard Book Number (ISBN) Procedure A correctly coded 10-digit ISBN a1 a2 …a10 has the property that 10a1 + 9a2 + 8a3 + 7a4 + 6a5 + 5a6 + 4a7 + 3a8 + 2a9 + a10 is evenly divisible by 11. A very detailed check! Let’s check the For All Practical Purposes textbook! ISBN 10(0) + 9(7) + 8(1)+ 7(6) + 6(7) + 5(6) + 4(9) + 3(3) + 2(9) + 5 = 253 253….11 x 23 = 253 If ISBN was… X 10(0) + 9(7) + 8(1)+ 7(6) + 6(7) + 5(1) + 4(9) + 3(1) + 2(0) = 199 199/11… x 19 = 209 199 + ____ = would make 11 digits, so we use X

International Standard Book Number (ISBN) Error Detection Detects 100% of single errors Detects 100% of transposition errors

VIN System – Vehicle Identification Number The manufacturer gives each automobile a unique VIN. A typical VIN has 17 alphanumeric characters that code information such as country where vehicle was built, manufacturer, make, body style, engine type, plant where vehicle was built, model year, model, type of restraint, a check digit, and a production sequence number.

Vehicle Identification Number (VIN) Procedure Check Digit is the 9th Digit Convert the Letters to Numbers Assign them the weights according to their position….remember to leave 9th digit out of the mix! Add the products Divide the sum by 11 Check Digit is the remainder!

VIN Example 1G1BL52P7TR115520 (note '7' is the check digit) Convert letters to numbers Assign weights Divide by 11; Check Digit is remainder

Chapter 16: Identification Numbers The ZIP Code
Identification numbers sometimes encode geographic data. In 1963, the U.S. Postal Service numbered every American post office with a five-digit ZIP code—numbers begin with 0 at the points farthest east, and work up to 9 at the points farthest west. In 1983, the U.S. Postal Service added four digits to the ZIP code, ZIP + 4 code. 32

Chapter 16: Identification Numbers The ZIP Code
Consider the ZIP Code 55812 The first digit represents one of 10 geographic areas, usually a group of states. (9) is farthest West (0) is farthest East The second two digits, in combination with the first, identify a central mailing distribution known as a sectional center. The last two digits are the town or local post office. Rule of thumb…usually alphabetical (towns that start in “A” have smaller numbers). In many cases…largest town given “01” and surrounding towns in alphabetical order

Chapter 16: Identification Numbers Bar Codes
Bar Code – A bar code is a series of dark and light spaces that represent characters. Bar Codes Bar coding is a method for automated data collection. The identification number is changed into a bar code. The bar code can be decoded by using a beam of light that is passed over the bars and spaces via a scanning device, such as a hand-held wand or fixed-beam device. The differences in reflection intensities (black vs. white bars) are detected by the scanner and converted to a string of 0’s and 1’s that represent specific numbers and letters. These strings are called binary coding. Binary Code – Any system representing data with only two symbols is a binary code.

ZIP Code Bar Code The simplest bar code is the Postnet code used by the U.S. Postal Service and commonly found on business reply forms. UPC Bar Code The UPC bar code was first used on grocery items in 1973 and has since spread to most retail products. 35

ZIP Code Bar Code

Chapter 16: Identification Numbers ZIP Codes
In 1993, large organizations and businesses that wanted to receive reduced rates for ZIP + 4 bar-coded mail were required to use a 12-digit bar code called the delivery-point bar code. This code permits machines to sort a letter into order in which it will be delivered Mail for the first location on the mail route occurs first, mail for the second location on a route occurs second, and so on… 12 Digit Bar Code 9 Digit ZIP + 4 followed by the last two digits of the street address or box number and a check digit so the sum of all 12 digits is evenly divisible by 10

Chapter 16: Identification Numbers Encoding Personal Data
Encoding – translating data into code. Coding License Numbers Some states assign driver’s license numbers with personal data encoded into the number. Personal data that may be encoded are name, sex, and date of birth. Coding license numbers solely from personal data enables automobile insurers, government entities, and law enforcement agencies to determine the number from the personal data. Social Security Numbers There is no personal data encoded in the Social Security number The Social Security numbering scheme predates computers. The only personal information that can be deduced from the Social Security number is where the holder obtained it. The first three digits show (the state usually) where the applicant applied, with a few exceptions.

Chapter 16: Identification Numbers Encoding Personal Data
Soundex Coding System Delete all h and w Assign numbers to remaining letters a, e, i, o, u, y – 0 b, f, p, v – 1 c, g, j, k, q, s, x, z – 2 d, t – 3 l – 4 m, n – 5 r – 6 Two or more letters with the same value in a row – omit all but 1st Delete first character of original name if still present Delete all occurrences of a, e, i, o, u, and y Only first three digits and first letter of Last Name

Chapter 17: Information Science Cryptography
Crytptology In many situations, there is a desire for security against unauthorized interpretation of coded data (desire for secrecy). Hence came cryptology, which is the study of how to make and break secret codes. Cryptology – The study of how to make and break secret codes. Encryption The process of encoding data (or simply disguising the data) to protect against unauthorized interpretation. Decryption The process of decoding the message to be able to correctly interpret it.

Types of Cryptosystems: Caesar Cipher A cryptosystem used by Julius Caesar whereby each letter is shifted the same amount. Not much effort to “crack” this code! Vigenére Cipher A cryptosystem that uses a key word to determine how much each letter is shifted. Key word – A word used to determine the amount of shifting for each letter while encoding a message.

RSA Public Key Encryption Scheme – A method of encoding that permits each person to announce publicly the means by which secret messages are to be sent to him or her. In honor of Rivest, Shair, and Adleman, who discovered it. The method is practical and secure because no one knows an efficient algorithm for factoring large integers (about 200 digits long). Cryptogram – A cryptogram is a sentence (or message) that has been encrypted. Cryptography is the basis for popular word puzzles, called cryptograms, found in newspapers, puzzle books, and Web sites. Cryptogram Tips – Knowing the frequency of letters may help: A widely used frequency table for letters in normal English usage.

Cryptogram Tips (continued) Here are some other helpful tips to know when solving cryptograms: One word consisting of a single letter must be the word a or i. Most common two-letter words in order of frequency: of, to, in, it, is, be, as, at, so ,we, he, by, or, on, do, if, me, my, up, an, go, no, us, am. Most common three-letter words in order of frequency: the, and, for, are, but, not, you, all, any, can, had, her, was, one, our, out, day, get. Most common four-letter words in order of frequency: that, with, have, this, will, your, from, they, know, want, been, good, much, some, time. The most commonly used words in the English language in order of frequency: the, of, and, to, in, a, is, that, be, it, by, are, for, was, as, he, with, on, his, at, which, but, from, has, this, will, one, have, not, were, or. The most common double letters in order of frequency: ss, ee, tt, ff, ll, mm, oo.

Chapter 17: Information Science Web Searches and Mathematical Logic
In 2004, the number of Web pages indexed by large Internet search engines, such as Google, exceeded 8 billion. The algorithm used by the Google search engine, for instance, ranks all pages on the Web using interrelations to determine their relevance to the user’s search. Factors such as frequency, location near the top of the page of key words, font size, and number of links are taken into account. Boolean Logic A branch of mathematics that uses operations to connect statements, such as the connectives: AND, OR, NOT. Boolean logic was named after George Boole (1815–1864), a nineteenth-century mathematician. Boolean logic is used to make search engine queries more efficient.

Chapter 17: Information Science Web Searches and Mathematical Logic
Expression In Boolean logic, an expression is simply a statement that is either true or false. Complex expression can be constructed by connecting individual expression with connectives: AND, OR, and NOT. Connectives, their math notations, and meanings: AND conjunction ^, means to find the results with all of the words. OR disjunction v, means to find the results of at least one of the words. NOT ¬, means to find the results without the words. Two expressions are said to be logically equivalent if they have the same value, true or false. Truth Tables – Tabular representations of an expression in which the variables and the intermediate expressions appear in columns, and the last column contains the expression being evaluated.

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