Oz – Foundations of Electronic Commerce © 2002 Prentice Hall Security and Privacy Issues

Oz – Foundations of Electronic Commerce© 2002 Prentice Hall

Security and Privacy Issues

2 Oz – Foundations of Electronic Commerce© 2002 Prentice Hall

Learning Objectives List the major threats to networked

information systems Suggest a security measure for

each threat to networked information systems

Explain encryption and how it supports electronic signatures and digital certificates


Learning Objectives Contrast the legitimate data-gathering

needs of businesses and government with individual privacy concerns

Discuss how the increased use of the Internet increases threats to privacy

Explain the relationship between consumer profiling and privacy issues


No security? No privacy? No commerce! Online security

From a corporate perspective - the ability to protect information sources from unauthorized access, modification, or destruction

From a consumer perspective - the perceived guarantee that no unauthorized party will have access to the transaction information


Privacy concerns: Most people resent losing control of

the collection and use of their personal information

Controversial issue


The threats


Hacking HackerHacker - a person who accesses an

information system resource without permission Almost always the first step towards

criminal activity


Web site page defacement The malicious alteration of text,

graphics, or audio content of pages May range from a cyber equivalent

of graffiti to valid pages being replaced with offensive comments


Viruses Computer virus - a malicious

program that spreads through the exchange of files on disks or through networks Viruses that spread on their own through

networks are also called worms Viruses that have to be downloaded are

called Trojan horses


Denial of service (DoS) Occurs when, due to hectic malicious

activity, an organization cannot serve its clients Flooding the servers with logins

Distributed denial of serviceDistributed denial of service (DDoS) - the attackers “hijack” hundreds of systems (zombieszombies) that simultaneously attack a site Impossible to stop


Spoofing Usually means deception with the

purpose of gaining access, or making users thing that they are logged on a given site, when in reality they are logged on to another site Done by taking advantage of

vulnerabilities of the DNS system A serious spoofing attack may result

in massive fraud


The remedies


Authentication and confidentiality Authentication - the ability of the

system to verify that the users are who they “say” they are

Access codes ““what you know”:what you know”: userID and password ““what you are”:what you are”: biometrics

Unique physical features used for authentication


Confidentiality = no one except the user and the system (or counterpart in an exchange) is able to know the content of an exchange EncryptionEncryption methods

Can also be used for authentication


Transparency Trade-off between security and

convenience TRANSPARENCYTRANSPARENCY is achieved when

security measures are in place but are not noticeable to the users


Firewalls Firewall - hardware and software

whose purpose is to block access to certain resources Controls communication between a

trusted network and the “untrusted” Internet


DeMilitarized Zone (DMZ) approach - the link between 2 servers, one of which is a proxy server A proxy proxy serverserver “represents” another

server for all information requests Operated by an ISP Double firewall architecture: both the

internal network server and the proxy server employ firewalls


Antispoofing measures The telecommunication companies

that operate parts of the Internet must adopt spoof-proof software Encryption based

Ex.: DNS Security (DNSSEC)DNS Security (DNSSEC) allows Web sites to verify their domain names and corresponding IP addresses using digital signatures and public key encryption


Backup Ideally, backup files should be

updated in real time The backup fully reflects the original

Backup files should be stored off-site Specialized companies


Encryption and its applications


Encryption Encryption - the conversion of data

into a secret code Decryption - the conversion of the

secret code back into readable data Mathematical algorithms based on

key(s)key(s) The algorithm is not secret, only the

key is


The key is a binary number, 40 to 128 bits long The larger the key, the more difficult

it is to decipher the secret code The key is used both in encrypting

and in decrypting the data


Symmetric keys: Both sender and recipient use the

same, agreed upon, key Difficult when the same person has to

communicate with many people A different key is required for each

recipient


Asymmetric keys: The sender uses one key to encrypt the

message, while the receiver uses a different related key to decrypt it

Most common: public key method Each person has both a private and a

public key The private key is secret, while the public

key is freely distributed


Electronic signatures Several forms:

User signs with a stylus on a special pad

Use a biometric of the signer


Digital signatures An encrypted digest of the text that is

sent with a message AuthenticatesAuthenticates the sender of the

message Guarantees that the message was not message was not

alteredaltered Involves two phases:

The encryption software uses a hashing hashing algorithmalgorithm to create a message digest

The message digestmessage digest is encrypted using a private key


Digital certificates Files that serve as the equivalent

of ID cards Must be used by both buyers and

sellers to authenticate a digital signature

Issued by certificate authorities Also issue private and public keys


A digital certificate contains: Its holder’s name A serial number Expiration date The holder’s public key The digital signature of the certificate

authority


Secure Sockets Layer, SHTTP, and PGP

Secure Sockets Layer (SSL): Uses public key encryption The most popular security standard on

the Internet Secure HyperText Transport

Protocol (SHTTP): An alternative to SSL that only works

with HTTP


Pretty Good Privacy (PGP): Used for secure private

communications Works in conjunction with the e-mail

program Must register the public key with a

PGP server


Business continuity plans Almost all businesses are

dependent on the continuous availability of information systems Especially important for online

businesses Downtime - the time during which

systems are not functional


Companies must have a clear business continuity plan Also known as business recovery

plan Encompass:

Hardware Software People Tasks

Must be periodically reexamined


Privacy

The ability of individuals to control information about

themselves


Generally, the law does notnot give people ownership of information about themselves Legal limits on the collection and

dissemination of information exist Right to privacy is impliedimplied in the US

Constitution


Threats to individual privacy: Government

So far, the Internet has been used very little to collect information about citizens

Business Always interested in information about

their customers Especially true about retailers


Business needs Consumer information used primarily

to provide better customer service, and more effective targeted marketing

Individuals’ fears Consumer profiling Customer data as a saleable asset

To self-regulate or not to self-regulate?


Monitoring at the work place E-mail privacy

E-mail policies Web-browsing privacy

Policies about surfing the net for nonbusiness purposes


Security and Privacy Issues

Documents

Oz – Foundations of Electronic Commerce © 2002 Prentice Hall Security and Privacy Issues