Ingredients of Information Security

- Who has access the asset?

- Is the asset correct?

- Is the asset accessible?

…uncorrupted?…authentic?

What assets need to be secured?

Quality of Information System (IS) reflecting local correctnessand reliability of the operating system; the logical Completeness of the hardware and software implementing the protection mechanisms; and the consistency of the data structures and occurrence of stored data.†

† Definition from National Information Systems Security

Assurance that information is not disclosed to unauthorizedpersons, processes, or devices.†

† Definition from National Information Systems Security

Timely, reliable access to data and information serviced forauthorized users.†

† Definition from National Information Systems Security

spoofing playback (replay) attack man in the middle attack dumpster diving password cracking denial of service (DoS) attack shoulder surfing

network infrastructure attack

network scanning

buffer overflow

syn flood

AssetAsset

Security System

AttackProperAccess

At the root of all security is trust.

What don’t you (or shouldn’t you) trust??

Since we obviously can’t trust everything, we need to develop and implement security policy...

A security _________ defines what needs to be done.

A security ______________ defines how to do it.

All passwords must be updated on a regular basis and every one must include at least

one embedded non-alphabetic symbol.

example security policy

corresponding security mechanisms

AssetAsset

Security System

Security is about building barriers to protect assets.

What complicates security is the necessity for barrier penetration.

AttackProperAccess

To be secure the barrier holes must be guarded.

Basic Concepts in Barrier Penetration Control

- Can you prove it?

- That which you are permitted to do.

- You should be held responsible.

- Who are you?

Security systems need to be able to distinguish the“white hats” from the “black hats”. This all begins with identity.

What are some common identifiers used in our world?

What is the problem with using people’s names as identifiers?

Access privileges granted to a user, program, or process.†

† Definition from National Information Systems Security

Common authorization tokens:

Security measure designed to establish the validity of a transmission, message, or originator,or a means of verifying an individual’s authorization to receive specific categories of information.†

† Definition from National Information Systems Security

Authentication ... is a basis for trust

Password -- the most common means of authentication

Passwords are vulnerable to attacks. Why?

Uses challenge - reponse protocol

RESPONSE

password:

CHALLENGE

(Encryption required)

Challenge-response systems fail when responses are efficiently discovered.

Give password cracking software a challenge.The conventional wisdom is as follows...

Use first letters from some phrase you can remember.

TtlsH1wwya

Don’t use short passwords (at least 12 symbols).

Include both lowercase and uppercase and digits.

Bracket the password with non-alphanumerics.

#TtlsH1wwya&

Bracket the password with non-alphanumerics.

#TtlsH1wwya&

Alt - 0181

cracker algorithm == repeatedlycracker algorithm == repeatedly

token -- small device carried by user(often includes microprocessor, keypad and/or real-time clock)

Challenge-Response Token1) System displays random number which user enters on keypad.2) Card uses keypad input to calculate and display number.3) User enters number in computer which system verifies by same computation.

Time-Based Token1) Card uses internal real-time clock value to calculate and display number.2) User enters number in computer which system verifies with its clock.

HHAD - Hand Held Authentication Device

biometric -- requires special devices to read human features

digital certificate -- a certificate authority performs a security checkon a user and grants an electronic certificate (essentially encryption keys)

smartcard -- physically requires reader, contains full microprocessor with cryptographic calculations performed onboard.

Smartcards can store ...

Tampering with a smartcard typically renders it useless.

...what you _______ (password)

...what you _______ (key, token, smartcard)

...what you _____ (biometrics - fingerprints, retinal scan)

..._______ you are (in secure location, at some terminal)

Assurance the sender of data is provided with proof of delivery and the recipient is provided with proof of the sender’s identity, soneither can later deny having processed the data.†

† Definition from National Information Systems Security

Access

Attacker

User