Post on 11-Jan-2016
Robert H Deng, SIS-SMU, 2005 1
Lecture 5
E-Banking
Robert H Deng, SIS-SMU, 2005 2
Outline
• Definition of e-banking• Entity authentication and secure communications• Server side architecture & security• Web client security • Web application security
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What Is E-Banking
• Definition– The automated delivery of new and traditional
banking products and services directly to customers through electronic, interactive communication channels.
• Products and Services– Account information and management– Bill presentation and bill payment– Loan applications and approval– Investment and brokerage services– …
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Stages of E-Banking
• Automatic Teller Machine (ATM): – An economical substitute for brick and mortar branches, longer
banking hours– Services: Balance enquiry; cash withdrawal, deposit, funds
transfer, payment for IPO offerings, COE bidding, etc
• Tele-Banking:– Retail banking by dial a phone #, automatic voice response– all services as ATM except cash withdrawal and deposit
• PC-Banking – Dial into a bank’s intranet proprietary software system to access
accounts for transactions
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Stages of E-Banking: Internet-Banking
• Definition:– Consumers access banking products and services over the Internet
• Advantages– PC-banking were proprietary, developed just by the bank– Internet puts everyone on an equal footing. There is a wealth of 3rd party
providers– The cost per transaction through the Internet is 27 times less than
through ATMs, 54 times less than that of a telephone transaction and 107 times less than that of a physical branch transaction.
• The Risks– There is security risk in using any remote-access for financial services,
internet banking poses the greatest risk since internet is an open and public network.
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Internet Banking - Informational Websites
• Objective– Bank wants to provide
information to the public and its customers
– Bank wants to verify the information is correction and the web site is usually up
• Risk issues– Potential liability for inaccurate
information – Potential liability for spreading
viruses and other malicious code to computers accessing the website
– Negative public perception if the bank’s online service is disrupted or website defaced or presents offensive material
Inside ABC BankCompany InformationInvestor RelationsNews RoomCareersABC Bank in the CommunityDoing Business with ABC Bank
Help CenterContact UsATM/Branch locationsSelf ServicesFrequently Asked Questions
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Internet Banking – Transactional Websites
• Objective– Provide banking services in a secure
and reliable manner• Risk Issues
– Higher risk than info website due to exchange of confidential customer info and transfer of funds
– Authentication processes– Liability for unauthorized transactions– Losses from fraud if the bank fails to
verify user identity– Violations of laws or regulations
pertaining to consumer privacy, anti-money laundering, anti-terrorism etc
– Negative public perception, customer dissatisfaction, liability resulting from failure to process 3rd-party payments as directed or within a time frame.
Inside ABC BankCompany InformationInvestor RelationsNews RoomCareersABC Bank in the CommunityDoing Business with ABC Bank
Help CenterContact UsATM/Branch locationsSelf ServicesFrequently Asked Questions
Access Accounts
Personal Account LoginCommercial Account Login
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Consumer Switch Banks Due to Identity Theft
• close to 60% expressed concern about identity theft• 6% switched banks to reduce their risk of becoming a victim of identity theft
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Outline
• Definition of e-banking• Entity authentication and secure communications• Server side architecture & security• Web client security • Web application security
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Working with a Simplified Model
User InternetWebsitein DMZ
Bank’sNetwork
AuthServer
Database
• Security requirements– User authentication, confidentiality and integrity– How about non-repudiation?
• Possible means of user authentication:– Using user’s public key certificate– Using smart card and possibly in combination with biometric– Most e-banking systems use PIN (or password); backward
compatible with legacy systems
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Using SSL for Internet Banking
UserWebsitein DMZ
Bank’sNetwork
AuthServer
Database
• Secure communication over internal network– Communication between web server and bank’s internal servers are protected using
IPSEC (Internet Protocol Security)
• Secure communication over the Internet– Bank obtains public key certificate from a CA– Bank’s private key kept at web server, ideally in a tamper-resistant hardware– User and web server runs SSL, authenticate server and set up a secure tunnel
• Customer authentication– Customer sends PIN in clear text over the secure tunnel
Internet
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Using WTLS for Wireless Banking
UserPub or Priv
NetworkWebsitein DMZ
Bank’sNetwork
• Secure communication from WAP gateway to bank internal servers– Communication between web server and bank’s internal servers using IPSEC;
communication between WAP Gateway and web server using SSL
• Secure communication over the Internet– Bank obtains an ephemeral public key certificate for the WAP Gateway from a
CA (valid for 25 hours)– User and web server runs WTLS (Wireless Transport Layer Security),
authenticate gateway and set up a secure tunnel
• Customer authentication– Customer sends PIN in clear text over the tunnel
WirelessNetwork
WAPGateway
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The Security “Gaps”
• “Web server gap”: In “SSL for Internet Banking”, cleartext appears in the web server, which may be in house or hosted by a service provider; web server is vulnerable to attacks
• “WAP gaps”: In “WTLS for Wireless Banking”, cleartext appears in WAP gateway (which is normally hosted by a cellular operator) and in the web server
• Directive from a central bank: “all PINs must be protected end-to-end, from customer terminal to bank’s authentication server”.
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Outline
• Definition of e-banking• Entity authentication and secure communications• Server side architecture & security• Web client security • Web application security
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Server Side Architecture & Security - Demilitarized Zone (DMZ)
• DMZ– A semi-trusted network zone to segment off systems that
accessed by Internet users from those that are accessed by internal users and servers
• DMZ policy rules– Any system that can be directly contacted by an external user
(web server, external mail server, external DNS server, etc) should be placed in DMZ.
– DMZ systems are always under attack and can not be trusted, should be severely restricted from accessing internal systems. Ideally, internal system should initiate connection to DMZ systems.
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Server Side Architecture & Security - A typical DMZ architecture
InternalNetwork
InternetFirewall
Web Server
ExternalMail Server
ExternalDNS Server
Only services offeredby DMZ systems
Responseonly
Initiateconnections
DMZ
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A Typical E-Banking Server Side Architecture
Bank InternalNetwork
Internet
Firewall1
E-bankingApp Server
WebServer
DatabaseServer
HSM
HSM – Hardware Security Module
F/W only allows accessports 80 and 443 on the web server
Firewall2
Firewall3Makes SQL queries to
database server
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E-Banking Server Side Architecture- Web Server, App Server, Database Server
• Web Server– Sensitive information: Open to access from the Internet; is at most semi-
trusted. Should not store sensitive information; PINs only transit through it, should not be kept on it
– Server location: Firewall1 only allow access to ports 80 and 443 on web server
– OS configuration: Remove all unnecessary services; Check for and load latest patches
– Dual home web server, one interface for web traffic and responds to customer; another (may resides on a 2nd DMZ) handle application queries to the e-banking server
• E-Banking Server– process customer requests, makes SQL queries to the database server
and provides information to the Web server for presentation to customers
• Database Server– contains lots of sensitive information, is located in the internal network,
no Internet connection
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E-Banking Server Side Architecture- Communication with Database Server
• Ideal solution– e-banking app server does not make connection to database
server, but the latter initiate connection to the former; – however this delays response and is not acceptable
• Practical solution– e-banking app server uses an ID and secret key to access the
database, but the secret key may be compromised. – make the ID very restrictive, e.g., read access to non-sensitive
information– couple e-banking app server ID & secret key with customer
authentication information to access the customer sensitive information
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A High Availability E-Banking Server Side Architecture
App layer switches provideload sharing & fail-over across
web servers
Routers & firewalls arecross-connected to switchesto provide redundant paths
App layer switch Firewall Switch Router
Internet
ISP #1 POP
ISP #2 POP
BGPrunningbetween
ISPs
Web servers
e-banking app servers
Internalnetwork
Database serveron redundant cluster
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Outline
• Definition of e-banking• Entity authentication and secure communications• Server side architecture & security• Web client security • Web application security
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Web Spoofing
Victim’sbrowser Attacker
Web Server
1. Requestspoofed URL
2. Requestoriginal URL
3. Original pagecontents
4. Change page
5. Spoofed pagecontents
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Web Spoofing
• Attacker 1. makes victim visit his web page (e.g., by phishing attack)2. either sends victim a fake page or passes on the original URL request
to the real web server (e. g., function as a proxy)3. intercepts response4. may change the response5. sends the response to victim
• Consequences– Attacker may get victim’s account and password, may spoof stock
market information
• Difficult to counter– Victim may not be able to recognize it’s fake. Browser’s location line
and status may be changed by attacker using JavaScript– Victim needs to examine SSL certificate’s owner carefully!
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Phishing Attack
• One of the most prolific identity theft attacks, especially targeting e-banking users
• Some recent statistics (figures for Oct 2004, based on Comodo Inc unless otherwise stated):– Some 57 Million US Internet users have identified the
receipt of an e-mail linked to a Phishing scam --- Gartner 2004
– Number of active Phishing sites: 1142– Average monthly growth rate July-Oct 2004: 25%– Country hosting the most Phishing websites: USA
Average time online for a site: 6.3 days– Longest time online for a site: 31 days
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Mounting Phishing Attacks
• Attacker directs victim to a malicious website typically via e-mail spoofing
• E-mail spoofing: E-mail seems to origin from a trusted company and urges users to follow a hyperlink referring to a malicious server having a web domain name similar to that of the spoofed site. Examples:– http://www.signin.abcbanker.com, easily confused
with http://www.signin.abcbank.com. – http://www.paypal.com@the.attacker.com, refers to
the.attacker.com instead of www.paypal.com which is interpreted as a login name instead of an address
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Phishing Attack to DBS Singapore's DBS warns of fraudulent site in Hong Kong
Posted: 11:02 PM (Manila Time) | Dec. 27, 2003Agence France-Presse
SINGAPORE -- The Hong Kong Monetary Authority and police are working to shut a fraudulent online banking website claiming to be a part of Southeast Asia's largest lender DBS Bank, the Singapore-based bank said.
"DBS Bank wishes to advise that this website has no affiliation whatsoever with DBS Bank, nor the Group," the company said in a statement on its website. "DBS Bank has reported the fraudulent website to the Hong Kong Monetary Authority and the police, who are working with relevant authorities to shut down the fraudulent website."
The fraudulent website, www.dbshk.net, has two small boxes for customers to fill in their account names and passwords to access a list of online banking services.
It features the bank's distinctive red logo and even a picture of the smiling female bank teller clad in the grey uniform that greet online customers on the actual Internet site.
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Outline
• Definition of e-banking• Entity authentication and secure communications• Server side architecture & security• Web client security • Web application security
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Web Application Security
• More and more web based applications; they are becoming one of the major targets for attacks– 70% of new attacks target the web (SQL injection,
buffer overflow, etc)
• Network based firewalls and IDS are entirely blind to encrypted web traffic
• Firewalls let in web traffic through ports 80 and 443
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Web Application Security Gateway
Flash Demo: http://www.teros.com/products/appliances/gateway/attacks_defeated.shtml
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Summary
• Definition of e-banking• Entity authentication and secure
communications (the “gap” problem)• Server side architecture & security (DMZ policy
rules)• Web client security
• Web application security and application security gateway
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• Reading assignments:
– http://www.ffiec.gov/ffiecinfobase/html_pages/ebanking_book_frame.htm