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Introduction toComputer Security

Security Terminology, PasswordGuidelines, E-mail and Web

Security

Topics

Common Security Terminology

Password Security

E-mail Security

Web Security

Peer-to-Peer Filesharing

Terminology

Password Cracking Password Cracker

An application that tries to obtain a password byrepeatedly generating and comparing encrypted

passwords or by authenticating multiple times toan authentication source.

Common Methods of Password Cracking Brute Force = attempts all possible character

combinations

Dictionary = attempts pre-determined charactercombinations

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Terminology

Password Cracking (contd) Passwords are usually stored in an encrypted

form with a one way encryption algorithm

If this data is compromised, password cracking can

be moved to a standalone system for easiercontrol and speed of cracking

Terminology

Biometrics

Science and technology of measuring and

statistically analyzing biological data.

When used in Information Technology itusually refers to the use of human traits for

authentication

This can include fingerprints, eye retinas and

irises, voice patterns and a host of otherconsistent biological data

Terminology

Public Key Cryptography Two keys, a.k.a. certificates, are available

for each resource, one public and one private

As the names imply, the public key can be

shared freely while the private key is keptsecret

Items encrypted using the public key aredecrypted with the private key and converselyanything encrypted with the private key canbe decrypted with the public key

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Terminology

Public Key Cryptography (contd) This method of encryption is used to ensure

secure communication is only between avalid, known, sender and recipient

Terminology

SSL

Secure Sockets Layer

Uses Public Key Cryptography

Negotiates a method to encrypt communicationbetween a client and server

Allows other network protocols to connect over topof it, such as web browsing and e-mail protocols

Transport Layer Security (TLS) is a variant of SSLused to negotiate encryption within the networkprotocol being used

Terminology

Man-in-the-Middle Attack

A system between two hosts that either

passively watches traffic to gain informationused to replay a session or actively

interferes with the connection, potentiallyimitating the remote system

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Terminology

Zombies Computer systems infected by a virus or

trojan horse that allows the system to beremotely controlled for future exploits

These systems may be used to send large

amounts of spam email or take part inDistributed Denial of Service (DDoS) attacks

Terminology

Denial of Service Attack

Sending large amounts of data and requests

to a remote system in order to inundate theremote computer or network

A Distributed DoS is a a coordinated effort by

a number of systems to perform a DoS on asingle host

Terminology

Key Logging Software

Software installed on a system to capture and

log all keystrokes

Security Exploit A software bug, or feature, that allows access

to a computer system beyond what was

originally intended by the operator

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Terminology

Firewall Network device or software used to filter traffic

to and from the connected resources

Ranges from simple filters, blocking certain

services and protocols, to more complex

systems that plot traffic patterns

Local operating system firewalls are referred

to as personal firewall software

Terminology

Terminology

Where to find technology definitions

www.webopedia.com

www.whatis.com

www.techweb.com www.computeruser.com

www.google.com

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Password Security

According to CERT/CC (ComputerEmergency Response Team /Coordination Center) approximately 80%of all network security issues are causedby bad passwords.

Computer to Computer authentication canuse large keysets and complex encryptionwhile Human to Computer authenticationrelies on much easier methods

Password Security

How to deal with password limitations

Expiration

Decreases chances of cracking passwords

Complexity Requirements

Decreases ability of automated attacks byincreasing possible character combinations

Length Requirements

The longer the password the more possiblecharacter combinations

Password Security

How to deal with password limitations

Password Lockouts

If a certain number of login attempts fails within agiven timeframe the account is locked for a preset

time period Stops brute force authentication attempts

Dictionary Checks

Simple checks against common dictionaries areused to increase password complexity

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Password Security

Are password rules too complex? Computer hardware speed and price are

always dropping

Post-it Notes

Is your computer in a locked room?

Who has physical access to your system?

A majority of system attacks originate through the

network.

Password Security

Suggestions for Complex Passwords

Think of a phrase and use the first characters

of each word, mix case and use numbers andspecial characters

It is good to change your password every 6 months= Iig2cyPe6m

UI Vandals are number one = UiVdlsR#1

Password Security

Future Password Requirements

Decreasing password expiration times

Certificate authentication

Biometrics Two part identification, password and physical

item

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Password Security

Passwords are like Underwear! Dont leave yours lying around

Dont share them with friends

The longer the better (warmer?)

Change yours often

Be mysterious

Password Security

E-mail Security

E-mail Security Common E-mail Protocols

POP Post Office Protocol

Older protocol for downloading messages from an INBOX

IMAP Internet Message Access Protocol

Full featured mail folder access SMTP Simple Mail Transfer Protocol

Standard for sending and receiving e-mail between clients andservers and from server to server

MAPI Mail Application Programming Interface A set of communication methods and standards used

predominately for communication between Microsoft e-mailclients and servers

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E-mail Security

Secure e-mail protocols at the University POPS POP over an SSL connection

IMAPS IMAP over an SSL connection

SMTP+TLS Negotiation of a TLS/SSL

connection after connecting

All popular e-mail clients allow the use ofthese protocols

E-mail Security

Digital Signatures and Encryption

Uses Public Key Cryptography

Allows secure signing of messages as wellas complete encryption

E-mail Security

Digital Signatures Creates a checksum of an email message

and then encrypts the message informationusing the senders private key.

The message is then sent, without encryption,along with the digital signature usuallycontaining the senders public key.

The recipient can decode the messageinformation using the public key and confirmthe message was not altered in transit

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E-mail Security

Digital Encryption Requires the sender to have the public key of

the message recipient

A message is encrypted completely by the

sender using the recipients public key

The recipient receives the message and uses

their private key to decrypt the message

E-mail Security

E-mail Security

What does this look like in e-mail clients? Outlook uses S/MIME natively for encrypting and

decrypting messages. A signed message has an iconthat looks like a red ribbon. An encrypted messagehas a lock icon.

Thunderbird also uses S/MIME and will display a keyfor an encrypted message and a pen for a signedmessage.

Many other e-mail clients use similar methods todenote these types of messages. You can usuallyclick on the icons to display additional informationabout the encoding

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Web Security

HyperText Transfer Protocol (HTTP) Modern web browsers are capable of using

multiple protocols to download contentalthough most data transfers use HTTP

Uniform Resource Locator (URL)

web address

protocol://server/resource

http://www.uidaho.edu/registration/

Web Security

SSL

Very important on insecure networks such as

wireless

How to verify SSL in a Browser

https the web address begins with https meaningthe connection is using HTTP over SSL

Look for a Lock Icon

Internet Explorer may display a Security Alert thatyou are about to view pages over a secureconnection

Web Security

SSL (contd)

Certificate Authorities

A CA is an entity that issues certificates

If you trust a CA you will trust the certificatesissued by that CA

Web browsers come with a standard collection ofcommon certificate authorities including Verisign,Geotrust, Thawte and a number of others

Be wary of untrusted certificates as it has the

potential of being a man-in-the-middle attack

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Web Security

SSL (contd)

Web Security

Spyware/Adware

Spyware is software designed to intercept or takepartial control of a computer without the express

consent of the operator

Adware is similar to spyware except it is usedprimarily for advertising purposes and may have

provided the user with information about its operation

Regardless of the network level security, when

browsing, spyware will have access to your data

Web Security

Web Browser Software Updates

Update, update, update!

Security exploits can use your web browser toaccess your system, install software, delete

data, spread viruses

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Peer-to-Peer Filesharing

Peer-to-Peer Filesharing, or P2P, is usingsoftware to facilitate the transfer of databetween two systems without the need fora central file server

Common P2P apps are: Kazaa

eDonkey

Morpheus

Gnutella Clients (Limewire, Bearshare)

Peer-to-Peer Filesharing

Issues to consider with P2P filesharing

Copyright issues

Spyware/Adware

Zombies

Remote Control

Key logging

Security exploits

Sharing unexpected information

Peer-to-Peer Filesharing

Install AntiVirus Software

Symantec Antivirus

Check for operating system and software

updates regularly Install Spyware Detection Software

Microsoft Anti-Spyware Beta

Spybot

Adaware

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Presentation Schedule

Tuesday

November 29th

2005

CommonsCrest

Wireless Network Security4:00pm

Free Tools for Investigating PC Hacks3:00pm

Securing Windows XP Desktop Systems2:00pm

Introduction to Computer Security1:00pm

Presentation Schedule

Wednesday

November 30th

2005

Commons

Horizon

Phishing, Dont Get Reeled In4:00pm

ISP Liability for Copyright Violations by TheirCustomers

3:00pm

Using Helix for Recovering from PC Hacks2:00pm

SEL Cybersecurity Solutions for the ElectricPower System

1:00pm

Tools for Finding and Removing Rootkits10:00am

Update, Update, Update: Patching Windowsand Office

9:00am

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Presentation Schedule

Thursday

December 1st

2005

CommonsHorizon

Viruses, Worms and Trojans Oh My!10:00am

Got Backup?9:00am