security for internet and web based application richard n. zobel department of computer science...

Security for Internet and Web Based Application

Richard N. Zobel

Department of Computer Science

University of Manchester

Oxford Road

Manchester, M13 9PL, UK

Email: [email protected]

ForThe 4th International Conference on

Information Integration and Web-based Applications and Services

September 10-12, 2002

Outline

Introduction. Provision of Secure Access to Services. Encryption and Decryption of Messages. Current System Technical Problems. Security Issues. Digital Signatures. Digital Watermarks. Network Attacks. Case Studies.

Introduction

WWW Provides Easy Access and Communication Requires Responsibility Mischief and Criminal Activities Opportunities and Problems of Provision of Security Compromise between Privacy and (Inter)National Interests Private Security and National Security Conflicts Human Rights Issues, Data Protection E-Business Emphasis on Communicating Users - Initially for

Simulators

Initial Login and Password Only Allows Access to the Registration Process Further Security Required for Various Activities

Related to Required Services

3 - Tiered Process GUI - the Interface Servlets for User Choices Security DataBase Access

Provision of Secure Access to Services

Vis ito r sLo g in R eg is te r Ex . R eg is tr a tio n F o r g o t P as s w o r d

G UI I n ter f ac es

Ex R eg S erv le t

Lo g in S er v le t O p tio n 1 S er v le t O p tio n 2 S er v le tF o r g o tP as s

S er v le t

En c ry p tio n /D ec r y p tio n

Us er T o k en

D atab as e


The following figures illustrate the Authentication Process: The Secure Federate Architecture The Software Implementation of the Architecture

The Principle Concerns the Provision and Acceptance of Personal Details: E.g. Those used by Current Banking Systems or their

EquivalentShort Cuts, Through PIN Codes are Allowed unless

CompromisedAuthentication May also be through Digital

Signatures, Authentication and Digital Certificates


Federate Ambassador

JNDI SM SPH

RTIAmbassador

Secure RTI

TCP/IP

Authentication /

Access Control

Mechanism

JNDI API

Naming Manager

JNI

Token Generating Component

JNDI SPI

LDAP

Federate Registration

Federate Viewer

Login Interface

Federate Ambassador

JNDI SM SPH

RTIAmbassador

Secure RTI

TCP/IP

Authentication /

Access Control

Mechanism

JNDI API

Naming Manager

JNDI API

Naming Manager

JNI

Token Generating Component

JNDI SPI

LDAP

Federate Registration

Federate Viewer

Login Interface


-Security Manager (SM)-Secure Protocol Handle (SPH)-Java Naming Directory Interface (JNDI)-Service Provider Interface (SPI)-Light Weight Directory Access Protocol (LDAP)-Java Native Interface (JNI)

Encryption and Decryption of Messages

Symmetric Keys Problems - Use Fast Computers to Crack Codes

Asymmetric Keys Public and Private Keys

RSA (Rivest-Shamir-Adleman) - Uses Integer Factorisation Given Public (Encryption) Key - Difficult to Determine

Private (Decryption) Key Degree of Difficulty relates to Number of Bits

1024 bits gives a Reasonable Degree of Security

Two distinct primes pi and qi are selected then

φ(pi)= pi-1, and φ(qi)= qi-1

if gcd(pi, qi )=1 then φ(pi qi)=φ(pi)•φ(qi) where φ(n) is called the Euler phi function, gcd is the greatest common

divisor If pi and qi are each 1024 bit long, it is almost impossible, given

present technology, to factor the modulus into pi and qi .

The sender chooses: Public key ei such that ei ≤ pi • qi where ei and φ(pi• qi) are

relatively prime. Private key di is computed such that ei ∙di=1(mod(pi -1)•(qi

-1)). The encryption function is e(pt)=pt^di mod pi• qi

where pt is the plaintext and pt< pi • qi. The decryption function d(ct)=ct ^ ei mod pi • qi where ct is

the cipher text. The sender has public key pair (pi • qi , ei) and private key di

The receiver has access to the public key of the sender

RSA Algorithm

An elliptic curve is defined by an equation of the form:

y = x + ax + b2 3

Elliptic Curves

y

x

P = (x , y )1 1

R = (x , y ) 3 3

Q = (x , y ) 2 2

G e o m e tric d e s c rip tio n o f the a d d itio n o f tw o d is tinc t e llip tic c u rv e p o ints : P + Q = R

Elliptic Curves

Current System Technical Problems

Security Level and Cost Balance No guarantee Clever Mathematics

Privacy and the Security Services Criminal and Law Enforcement Conflict between private individuals/organisations and security

services Human rights, data protection, computer firewalls, private protection Expect criminals to be detected and punished

Security, Secrecy and Confidentiality National and Cultural Differences

Digital Signatures

Equivalent to hand written signature ( but more repeatable !) More secure and useful:

Non-repudiation Guarantees of Authenticity and Integrity of data

Signature Derived from both the data and the signer, who has the public key Does not guarantee the signer is the owner of the public key This can be guaranteed by the use of Digital Certificates

Identity Certificates (eg X.509) - public key and sufficient data to identify the key holder

Accreditation - Identifies key holder as a group holder eg Doctor Authorisation – Used for delegation of authority

Digital Signatures

Certification Authority (CA) – An agent of trust in a Public Key Infrastructure (PKI)

Verifies user’s identities

Issues keys to users

Certifies users public keys

Publishes users Certificates

Issues Certificates revocation lists

Digital Signatures

As y m m etr icC ip h er

P r iv a te Key

M es s ag e D ig es t

M es s ag e

As y m m etr icC ip h er

P u b lic Key

C o m p ar e

Has hAlg o r ith m

Has hAlg o r ith m

D ig ita lS ig n a tu r e

D ig ita l S ig n a tu r e C r ea tio n D ig ita l S ig n a tu r e Ver if ic a tio n

Digital Watermarks

New area - ~ 7 years old Original watermark use – prevention of copying of bank notes

and legal documents Digital watermarks now have wider applications

Copyright protection images, text, multimedia data Identification of data ownership Identification of those who handle or receive it Tracing and proof of ownership Guaranteeing that images and data have not been tampered with

Proliferation of the use of “invisible” watermarking Identification and protection against attack

Digital Watermarks

Initial Applications in imaging Systematically modifying and image in minor ways

imperceptible to the eye Geometric modifications Stochastic modifications Spatial or frequency domain modifications Example of bank notes

Limitations Capacity to discretely contain the watermark Open to attack by use of image processing techniques

Identify presence of watermark Attempt to remove watermark

Digital Watermarks

Applications Images Sequence of images (subliminal !) Any data, including text and figures (.ps, .pdf .doc, .rtf, etc)

Map Errors Deliberate Identification for Copyright

O.S. (Ordnance Survey) Maps Euro currency notes - map of Europe

Network Attacks

Disclosure of data, mis-use of data Intruder attack More common - credit card details, use of private email Any data, including text and figures (.ps, .pdf .doc, .rtf, etc)

Corruption of data - Virus attack Destruction Modification Interception

Denial of Service Attack

Network Attacks

Secondary Victims

Master Agent Slave

Agent

Primary Victim

Attacker

Network Attacks

Forensic Profiling

Involves identifying, preserving and analysing digital evidence In a way which could lead to the profiling and conviction of offenders

Profiling gives a general biographical description of the most likely type of unknown offender

Two types of profiling Inductive - scientific approach using experimental, statistical,

correlation analysis Deductive - based on forensic evidence pointing to a particular crime-

scene and the behavioral reconstruction of the possible offender Problems

Lack of standards, poor analysis techniques, lack of specialists and inadequate training.

P ro filing M o d el

B ehavio r R ec o ns truc tio n

F o rens ic Evid enc e

C rim e S c ene A nalys is

V ic tim A nalys is

P ro file B y D ed uc tio n

C rim e A s s es s m ent

Inves tigatio n

A p p rehens io n

Forensic Profiling

A c tive C a s e -B a s e

G ra phic a lInte rfa c e A g e nt

G a the ringC o lle c tio n A g e nt

T ra c eA g e nt

R e trie va lA g e nt

P ro file -B as e

Forensic Profiling

G I A g e n t

agen t ID

req u es t A gen t L is tagen t D is p at chk illA gen t

G C A g e n t

agen t ID

execu t eA gen tagen t Q u ery

1 *

Forensic Profiling

G I A g e n tG C A g e n t

es t ab lis h co n n ect io n ()

[if co n n ect ed ]get A gen t L is t ()

s elect A gen t (),co n figu reA gen t ()

d is p at ch A gen t (agen t ID ,co n figIn fo )

act iv at eA gen t (),s t art E xecu t io n ()

,get R es u lt t ()

s t o p A gen t ()

Forensic Profiling

S ta rt

C o ns truc t T ra c e T a s k

E xe c ute

S uc c e s s F a ilure

a ny L ink

S to p

I n fo rm Tra ceA g e n t

I n fo rm R e trie v a lA g e n t

I n fo rm s Tra ceA g e n t a n d Upda te

Pro f ile -B a s e

Y e s N o

Forensic Profiling

Secure Simulation

Case Studies

1. Mobile Phones Analog phones had little or no security Digital phones offer much better prospects Current GSM phones offer some relatively unsophisticated

protocol and encryption standards As shown in the following figures

Ki is the subscriber’s authentication key A3 Algorithm is the signal response calculation (SRES) A5 Algorithm is the keystream generation calculation A8 Algorithm is the cyphering key calculation (Kc)

A3 + A8

A5

=

A5

S R E S

Au th en tic a tio n r es u lts

Kc

Kc

G S M N etw o r kM o b ilis a tio n

C h allen g e R es p o n s eM ec h an is m

Ki

E n c r y p tedC o m m u n ic a tio n

M S s ig n s o n

Au th en tic a tio n R eq u es tR A N D

Au th en tic a tio n R es p o n s e

C ip h er in g M o d e R eq u es t

SR E S

C ip h er in g M o d e C o m p le te

M S s ig n s o f f

Case Studies

Case Studies

P la in tex tAs y m m etr ic

C ip h erAs y m m etr ic

C ip h erP la in tex t

C ip h er tex t

P u b lic Key P r iv a te Key

Mobile Station GSM Network

1: MS request access to GSM network

2: GSM network generates data for MS to encrypt

3: MS encrypts data with its private key and returns data to network

4: GSM network decrypts data using the public key in the certificate

5: If data is the same as the original then authentication is successful

Case Studies

Case Studies

2. Distributed Interactive Simulation Involves real-time interconnection of simulations and

simulators on the network Initially developed for military systems - use ATM private

networks Many civil applications - use Internet, lack security

Use Internet Protocol Security (IPSEC) end-to-end mechanism for protecting data using tunneling

Alternatively use a virtual private network (simulates a private network over a public network such as the Internet) VPN, which can be enhanced through use of encryption and firewall and tunneling mechanisms

Case Studies

3. Distance Learning New research at Manchester (Computer Science)

Employs a remote and powerful simulation tool, which acts as a server, spawning simulations for use by course developers and students

Local use of an animator, which provides for interactive use of simulations running elsewhere in the network

Can be used for diverse dynamic systems simulation for continuous, discrete event or mixed systems in fields as diverse as mechanical engineering, finance and scheduling.

Conclusions

Security for Internet and Web based systems and users is now a major priority issue

Two Central Issues Achieving Secure Access to Systems Achieving Secure Access to Data

Four Central Facilities Authentication Certification Digital Certificates Trusted Certification Authority

Conclusions

All of these are needed for support of secure e-business and e-commerce.

Digital watermarks are of increasing importance

Attack problems Standards are needed

Some widely differing case studies have been presented. These illustrate the importance of networking and associated security issues.

security for internet and web based application richard n. zobel department of computer science...

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