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SECURITY
Bart Vansevenant
 Who is who?
 Who can read what?
 Traces
 Virusses
 Safety and confidentiality
Who is who?
Who can read what ?
 Telephone line
 Mail server
 TCP/IP
 Echelon & Carnivore
e-mail using an ISP
POST
OFFICE
SMTP
POP3
a) Telephone-line
POST
OFFICE
SMTP
POP3
b) e-mail server
Everything on the
servers can be read
or copied
POST
OFFICE
SMTP
POP3
c) TCP/IP
POST
OFFICE
SMTP
POP3
Not readable – following
different ways
Echelon/Carnivore
Source: http://www.fbi.gov/hq/lab/carnivore/carnlrgmap.htm
Traces
Traces
The IP address of your computer is : 213.177.129.120
your DNS address is : adsl-129-120.wanadoo.be
We know you use : Microsoft Windows 98
Your navigator has the code: Mozilla/4.78 [en] (Win98; U)
In fact it is: Netscape Communicator 4.x English
What you did is stored :
Windows 95
C:\Windows\Temporary Internet Files\
Windows NT C:\WinNt\Temporary Internet Files\
A nice demo in french on: www.cnil.fr
Virus
 What is a virus and types?
 How is a computer infected?
 Danger
a) What is a virus?
 computer virus = a computer program
'I love you', 45 million computers infected
 worm = multiplicates itself
code Red: 300.000 servers destroyed
 trojan horse = hides for other actions
Back Orifice
 logic bomb = distroys programs
 hoax = false alarm
b) How is a computer infected?
 files attached to e-mail
(attachment)
 diskettes
 other
c) Danger
 infecting components of your system
 effects:
malfunctions
deletion of data
wiping of hard disk
...
Solutions to provide safety and
confidentiality
 solving identity problem
and unauthorised reading
 protection against traces
 protection against virusses
Identity and unauthorised
reading
Encryption
 Purpose
 Functions
 How?
Functions of encryption

Authentication

Integrity

Confidentiality
Symmetrical encryption
SAME KEY
Sender
Receiver
A=A+1
Ubizen
Vcjafo
Encryption
E(…)
A=A-1
Untrusted
network
Vcjafo
Ubizen
Decryption
D(…)
Asymmetrical encryption
Public Key Receiver
Private Key Receiver
Sender
Ubizen
Receiver
Go#st$
Encryption
E(…)
Untrusted
network
Go#st$
Ubizen
Decryption
D(…)
confidentiality towards receiver
Asymmetrical encryption
Private Key Sender
Public Key Sender
Sender
Ubizen
Receiver
Go#st$
Encryption
E(…)
Untrusted
network
Go#st$
Ubizen
Decryption
D(…)
authentication of sender
Example
Example
Example
Against leaving traces
 Traces at the ISP
 Traces on own computer
Against virusses
 anti-virus program
Norton, McAfee, eSafe, F-Secure, …
 watch out for attachments
.exe, .com, .pif, .vbs, .doc, .xls, …
 www.bipt.be