nba 600: session 22 security and privacy networked world 10 april 2003 daniel huttenlocher
TRANSCRIPT
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Schedule For Rest of Term
Privacy and security (finish up today) Large networks (today and week of 4/14)
– Positive feedback effects– Small worlds phenomena– Smart mobs
Emerging technologies (week of 4/21)– Web services: J2EE and .Net
• Vision of Web-based business
– RFID – smart tags
Final project presentations (week of 4/28)
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Today’s Class
Finish topic of security– Malicious code (“malware”)
• Viruses, worms, Trojan horses
– Protecting your business• Differences between security in online
networked and offline physical worlds
Start topic of large networks– Physical, electronic, social and other networks
• Scientific, technical and business implications
– Certain properties that can be understood in terms of network structure/dynamics
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Malicious Code (“Malware”)
Dates back to early days of computing– Often as pranks, or to demonstrate possibilities
Some terminology– Virus: hidden program or piece of code that
“infects” some other program or file causing an unexpected, usually negative, result
– Worm: independent program that actively duplicates itself
– Trojan horse: malicious program that pretends to be a benign application• Generally must be deliberately installed
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Spreading Viruses
Most viruses today are scripts or macros that infect files or email– Because files and email are commonly
exchanged between people• Such viruses spread more quickly than other
means such as sharing programs
Viruses are always created by someone who intends to do harm– Often based on “templates”, so many similar
Virus scanners must be updated for each new virus, impossible to predict new ones
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Current Virus Prevention
Email filters that examine both incoming and outgoing email– Remove known viruses, automatically update– Replicate via address book or sent items
Scans of file systems for infected programs and files
Still can get “bitten” by new ones– Opening attachments can be dangerous
• Even if from someone you know because they may be infected
– Even viewing email in auto-preview panes can be problematic
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Worms and Trojan Horses
Less prevalent because harder to spread Worms tend to exploit flaws in servers
– Usually “buffer overflow” which allows code sent over network to be executed• Think of someone blindly following a recipe and
you can insert new steps they simply follow
– Recent one was Microsoft SQL server “slammer” worm• Widespread effect this past January
Trojan horses install unknown functionality– All downloaded programs a risk this way
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Protecting Your Business
Need good technology but not enough– Should be easy to use and fit with work
processes– Need to instill importance in employees and
have them contribute to security not evade
View computer and network security as a senior management issue– Policies set by CIO/CTO but agreed to and
followed by all senior managers– Likely to have more impact on employees and
business than physical security
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Some Security Rules of Thumb
Basic technology policies– Keep software patches up to date on all
externally accessible and critical systems• According to CERT prevents 95% of intrusions
– Use automatically updating anti-virus software– Use firewalls and network loggers– Have regular, automated, offsite backups
• Periodically test that restores work
Basic personnel policies– Information security is everyone’s
responsibility, broadly educate employees
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Passwords
Particularly difficult balance between security and usability– One-time token systems can help
External access particularly problematic– Wide range of remote attackers
Most passwords easy to crack– E.g., Dictionary lookups in matter of minutes– Even all possible 7 character passwords can be
tried in a few weeks
But policies can make worse
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Microsoft Trustworthy Computing
Initiative launched in early 2002– Across all product groups– Active involvement of research and academics
Goals are to provide– Security– Privacy– Reliability– Business Integrity– Products and services using software that are
as trustworthy as those using electricity• Took electric industry from 1880’s-1920’s
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Trustworthy Computing Goals
Security– Systems that are resilient to attack and protect
confidentiality, integrity and availability
Privacy– Customer able to control data about
themselves and those using data adhere to “fair information” principles
Reliability– Customer can depend on product to fulfill its
functions when required to do so
Business integrity– Vendor behaves responsively and responsibly
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Trustworthy Computing Means
Secure by design, by default and in deployment
Fair information principles– User data only collected or shared with consent
Availability – ready for use Manageability
– Easy to install and manage; scalable
Accuracy – functions correctly Usability – easy to use and suited to needs Responsiveness and transparency of firm
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Some Main Players in Security
VeriSign (VRSN)– Digital trust services– $1.2B/yr revenue, up 24% y-o-y (acquisition)– $2.3B market cap
CheckPoint Software (CHKP)– Firewalls– $427M/yr revenue, down 19% y-o-y– $3.9B market cap
RSA Security (RSAS)– E-Security solutions (e.g., secureID)– $230M/yr revenue, down 18% y-o-y– $420M market cap
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Large Networks
Networks underlying many aspects of both technological and social systems– Relationships: suppliers, customers, personal– Connectivity: supply chains, information
systems, online payment and delivery
Networks have some properties that are very different from “collections”– E.g., bell curve or normal distribution
• Height, weight, grades• Not incomes!
– Networks generally follow different distribution known as power law
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Properties of Large Networks
Positive feedback– Supply side economies of scale– Demand side economies of scale
• Often referred to as network effects
Tipping points Power law distributions Small worlds phenomena
– Power of long-range “random” connections
Evolution of networks Reputation in networks – “smart mobs”
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Positive Feedback
Supply side economies of scale– Marginal cost less than average cost
• Anything with high fixed cost, e.g., airline seats
– Information goods: (near) zero marginal cost
Demand side economies of scale– Network effects – value higher with more users– Physical and electronic networks
• E.g., phone system (first one studied)• Fax, email, IM, Web
– Societal networks• Software, VHS tapes, CDs, DVDs
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Positive Feedback Effects
“Tippy” markets– Sudden switch to strong get stronger, weak get
weaker
Winner take all markets– E.g., VHS vs. Betamax
Dominant player markets– E.g., Windows-Intel vs. Apple
Standards-based markets– Telecommunications: phones and Internet
Negative feedback– Can have stabilizing effect – multiple players
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Network Effects
Metcalfe’s law– Value of network proportional to square of its
number of users – n2
• Value to each user is (proportional to) n• Times n users
Physical and electronic networks– E.g., phone system
• Value proportional to number of people reachable by phone
– Communication networks in general– Tendency towards single provider or standard
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Societal Networks
Some non-networked goods exhibit network effects– Consumer software in general
• More valuable when someone you know can help explain it to you
Windows, TurboTax, etc.
• “Network” of know-how
– Stronger effect when software used to create documents• Word, Excel, Powerpoint, Acrobat• Inter-operability or standards issues important• “Network” of document exchange
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Number of Players
Single vendor/provider– Long distance (pre ATT breakup)– ATT connected their own local exchanges
• Enough local share to dominate long distance and lead to further aggregation
Interoperability among vendors/providers– Standards
• Internet has many providers all using common hardware and software standards
– Licensing• CD’s have many vendors all licensing common
standard from Philips
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Web Browsers
Substantial network effects– Easier for site developers to have one browser
or rock solid standard• Complex and (was) rapidly changing
True standards difficult to develop and maintain
Microsoft realized this and didn’t want to be the marginalized platform– In addition to bundling IE with the OS worked
hard to be compatible with market leader• IE 4 produced pages more similar to Netscape 3
than Netscape 4 did
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Lock In
Particularly high switching costs for products/services with network effects– Value of alternative lower until many users
• Decade-long transitions to new kinds of media E.g., vinyl to cassette to CD
• Difficulty for non-Microsoft Office software
Antitrust concerns specifically address network effects and resulting lock-in– E.g., AOL barred from upgrades to instant
messenger service unless interoperate with competitors
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Tipping Points
Malcolm Gladwell’s book Sudden changes that result from
seemingly small differences– Crime rates and policing– Epidemics of disease– Dominance of VHS over Betamax
Often underlying networks can provide some insight– Connections between people in spread of
disease, ideas, behaviors
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Dominant Player or Standard
Chances of tipping
Low High
Low LOW UNCLEAR
High NOT SOHIGH(airlines)
HIGH(telecom)
Economies of Scale
NetworkEffects
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Network Effects and IM
In 1999 AOL had near 100% of instant messenger market– With AIM and ICQ combined
In AOL Time Warner merger FCC prohibited advanced IM services such as video– Unless AOL opened up its services to
interoperate with other providers
AOL now about 48% of market, petitioning FCC to drop restriction– Claim no longer risk of “tipping”– MSN (29%) and Yahoo (23%) have added
advanced services such as video
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Causing Positive Feedback
Compatibility, inter-operability, standards– Ease consumer adoption– Multiple competitors, though not necessarily
anyone– Potentially give up some performance– Backward compatibility (e.g., dual band phones)
Going it alone– A “10x” product (Andy Grove)
• Much better than alternatives to help get over switching cost hurdle
– E.g., video game manufacturers
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Openness vs. Control
How much added value overall and share you can capture
Value added depends on– Product itself– Size of network
Your share depends on– Ability to capture the value– How open
• Resulting degree of competition
– Alliance vs. full openness
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No Guarantees
Customers value larger networks– How much depends on product/service
Expectations of who will win critical Tradeoff of openness vs. control Various strategies
– Standards• Room for innovation?
– Nearly identical technologies– Proprietary technologies
• Consortium – more control than with standards• Going it alone – high risk/reward