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PUBLIC KEY ENCRYPTION AND DATA SAFETY IN THE

INFORMATION AGE

By Nancy Larson and M. S. Trainer

The Information Age

The current era in history has been dubbed “The Information Age.” Sharing information quickly and electronically is the starting point of this moniker. An ever increasing amount of information is available wirelessly through computer systems. Books are stored on Google’s servers. Wikipedia allows everyone who registers to update the information. Educational institutions post research and grades online.

Corporations and organizations advertise on websites to advertise and inform. Medical groups maintain records electronically. Access to information is critical for our progress. Restricting access on a “need to know” basis is vital.

The History of the Internet

What is now referred to as “the Internet” began as a defense department project to ensure continuous communication for the military in the event of a nuclear war. The contract to construct the network was awarded in 1968 and the network was physically constructed in 1969 with only four hosts.

1 This network could not yet be called a public source.

Throughout the next twenty years the network grew in range and was increased in speed. In 1981 the

National Science Foundation developed CSNET to allow research institutions to communicate through

50 Kbps lines. The system of naming domains was established by the University of Wisconsin and the

TCP/IP protocols were put in place in 1983. By the mid-80s, the demand for service on the network increased and T-1 lines were implemented. Demand continued to increase and the development of the next generation of lines (to be called T-3 lines) began immediately. These lines (at 45 Mbps) were

1 History of the Internet2010. 27 March 2010. <http://www.davesite.com/webstation/net-history.shtml>

available by 1990. Through the 1980s and 90s, the internet transitioned from a military and research communication tool to a public communication tool.

2

By the mid-1990s, companies were finding ways to market through the internet. Microsoft’s Windows

98 provided a source of standardized internet access to a large number of consumers, both business and individuals. Other software companies followed suit. E-commerce was going strong, led by companies such as Amazon. The former military network was now used by a majority of the public in the United

States.

3 E-commerce brought the need for sharing private information securely from a public site.

Payment was usually made by credit card, so the number must be sent through the internet. The use of electronic records, accessible from multiple locations, has required a secure system which can transfer larger packets of information securely. These records are used in many fields, including education, banking and medicine. How are these records protected?

Protecting Data

Transferring data is possible because computers handle all information numerically. The letters of the alphabet are matched to numbers in a code referred to as ASCII. (See the table in Appendix A.) Each letter and number symbol is represented by a number. The computer does not use “E”. It uses 069. For

“e” the computer uses 101. The complete table is in the appendix. Since all data is represented by numbers, performing calculations on the numbers hides the data. The technique that is most commonly used for this is called public key encryption.

Founders of Public Key Encryption

2 Zakon, Robert. Hobbes' Internet Timeline. 1 January 2010. 25 March 2011

<http://www.zakon.org/robert/internet/timeline/

3 Howe, Walt. A Brief History of the Internet. March 24, 2010. Retrieved March 27,

2011.<http://www.walthowe.com/navnet/history.html>.

A trio of mathematical researchers proposed an asymmetric cypher in mathematical literature in 1976.

4

These researchers were Whitfield Diffie, Martin Hellman, and Ralph Merkle and the asymmetrical cypher became known as public key encryption. The paper published at that time provided a means of encryption, but the cypher to the encryption (the means to return the coded data to the original) would have to be transferred to the recipient of the communication. The transfer of the information that would break a code was a weak point in the encryption technique. Intercepting the cypher would allow the breaking of the code. But the paper published by Diffie, Hellman and Merkle proposed that an asymmetric function would solve this problem. There was only one drawback; no one knew of an asymmetrical function.

A group of researchers for MIT, that were located in East Africa, were determined to make the asymmetric function a reality. Ronald Rivest, Adi Shamir, and Leonard Adleman tried ideas and discarded them for over a year. Leonard Adleman was the mathematician of the group. Rivest and

Shamir were creative thinkers. They made a good team. Rivest and Shamir proposed ideas. Adleman found the fallacy in their proposals. Little time was wasted on ideas that would not work. In April 1977

Rivest proposed a solution that Adleman could not refute. 5

In August, 1977, Martin Gardner announced RSA public key encryption in the Games column of

Scientific American. (Gardner) The underlying premise of public key encryption is that the person receiving the information will choose two large prime numbers. (Prime numbers are those that can be evenly divided only be itself and one.) These two prime numbers are the private key. The product of these two primes, resulting from multiplication of the two prime numbers, is the public key together with a single digit number.. 6

Data Safety

4 Singh, Simon. The Code Book. New York: Random House, 1999.

5 Singh, Simon. The Code Book. New York: Random House, 1999.

6 Singh.

Are credit card numbers safe with a basic set of calculations like this? Are medical records secure? All the hacker would have to do is find one prime number that is a factor of the public key, and the second number will reveal itself, too. Luckily, it isn’t as easy as that. Martin Gardner, in the article that first announced public key encryption, challenged his readers to decode a cyphertext using a public key of

129 digits that he printed in the article.

7 Eighteen years later a group of 600 volunteers was able to break the encryption by factoring the public key. The group split the job into parts and used the computers and supercomputers in a parallel effort to succeed. One other point must be considered. The public key in this example was 129 digits. Many are 300 digits in length, vastly complicating the factoring. (Singh) Public key encryption makes other forms of hacking more appealing than breaking the key for encryption.

Locating the Public Key

Everyone who has purchased products online has used public key encryption. The computer user doesn’t need to enter the number. The public key is sent to the computer sending information by the computer that will receive the information. For the user it is invisible. The visible signals that encryption is in place are a padlock at the bottom left of the browser window and/or a web address that starts https:// indicating a secure site.

The public key can be regenerated as often as it is needed. How often that occurs is determined by a company’s security protocols. Based on prime numbers, the encryption has a large number of possibilities. The number of prime numbers is at this time limited, but the total number of prime numbers has been proven to be infinite. If, or when, a better method of finding prime numbers is developed, the flexibility of public key encryption will increase.

Usernames and Passwords

7 Gardner, Martin. "A new kind of cypher that would take millions of years to break." Scientific America

August 1977: 120-124.

Internal company websites, intranets, and emails often require a specific login, usually requiring a unique username and password for each individual. These websites will also use public key encryption when these passwords are transmitted. The double layer of encryption provides more security for the protection of proprietary information, personnel information and other information that the corporation wishes to protect. These types of security measures are also used for controlling access to medical and school records.

The choice of password also influences the level of security. Some corporations are now requiring sixteen characters in the passwords with upper and lower case letters and numbers included in every password. Some security software will check the password for recognizable words, names and phrases.

These weaken the password and are rejected by the security software. Randomly generated passwords are harder to break. However, passwords that are randomly generated are usually more difficult to remember. When the password is hard to remember, people are inclined to write it down, or save it on their computer. This reduces security. Choosing the length and security of passwords is a balancing act.

The Future of Security

The security issue will need to be constantly updated as the criminals become more adept at decoding or stealing the information to break current security measures. Public key encryption will be a strong part of network security for a long time in the future. The ability to access data from multiple locations provides more accurate medical records for the benefit of both doctors and patients, provides parents and students the opportunity to monitor grades throughout the school year and provides online banking and financial services at any hour of the day. This is the expected standard in the twenty-first century.

Appendix A

Table 1: ASCII Codes

Sample ASCII codes

063

064

065

066

067

068

069

070

071

072

073

074

ASCII value Character ASCII value Character ASCII value Character

048 0 075 K 102 f

049

050

1

2

076

077

L

M

103

104 g h

051

052

053

054

3

4

5

6

078

079

080

081

N

O

P

Q

105

106

107

108 i j k l

055

056

057

058

059

060

061

062

7

8

9

:

;

<

=

>

082

083

084

085

086

087

088

089

R

S

T

U

V

W

X

Y

109

110

111

112

113

114

115

116 q r s t m n o p

?

@

A

B

C

D

E

F

G

H

I

J

090

091

092

093

094

095

096

097

098

099

100

101

Z

[

\

]

^

_ a b c d e

117

118

119

120

121

122 y z u v w x

101

127

151

179

199

233

263

283

2

13

31

53

73

317

353

383

419

443

467

503

103

131

157

181

211

239

269

293

3

17

37

59

79

331

359

389

421

449

479

509

Prime Numbers

107

137

163

191

223

241

271

307

5

19

41

61

83

337

367

397

431

457

487

521

109

139

167

193

227

251

277

311

7

23

43

67

89

347

373

401

433

461

491

523

113

149

173

197

229

257

281

313

11

29

47

71

97

349

379

409

439

463

499

541

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