Security Matters V.T. Raja, Ph.D., Oregon State University

2Security Matters Outline –Summary –Example to illustrate RSA Algorithm –A framework to help managers understand their role in security

3Security Matters Summary from first lecture on Security Characteristics of Secure Communication Perfect security – a myth or a reality? Ciphers and Cryptography Authentication (ap ap 5.0)

4Security Matters Characteristics of Secure Communication

5Security Matters Cryptography Ciphers –Caesar, Monoalphabetic, Polyalphabetic Symmetric Key Cryptography (SKC) –Basic idea of SKC –Notation for symmetric key –Some popular SKC algorithms –Sharing of symmetric key

6Security Matters Public Key Cryptography (PKC) Basic idea of PKC Notation for private/public key pair and plain text message RSA Algorithm Sharing public key –Sender/Receive Authentication –Man (Woman) in the middle attack

7Security Matters RSA Algorithm How does RSA work? Class Participation Exercise on RSA application Why does RSA work? (See additional handouts for answers)

8Security Matters Example to illustrate RSA Algorithm Participation Exercise Background: –Bob has selected the prime numbers p and q as 5 and 7 respectively. –Bob has selected e to be the number 5. –Alice and Bob interpret each letter in the English alphabet as a number between 1 and 26. That is, a = 1, b = 2, …, n = 14,…, z = 26. –Alice wishes to send the plaintext “love” to Bob, after encrypting using RSA. Questions: –Compute Bob’s public key using RSA. –Determine Alice’s cipher text using RSA algorithm.

9Security Matters RSA Algorithm Even for small p and q, as seen in the participation exercise, we had to deal with extremely large numbers. If we follow the suggestion of RSA labs and select p and q to be several hundred bits long, then the following practical issues come to mind: –How to choose large prime numbers p and q? –How to choose e and d? –How to perform exponentiation with large numbers? (For those who are interested in this area, refer to Kaufman 1995 for answers to the above mentioned questions).

10Security Matters RSA and DES/AES DES is at least 100 times faster than RSA. In practice, RSA is often used in combination with DES or AES. How? (Alice encrypts DES key with Bob’s public key. Bob decrypts and obtains DES key with his private key. The data is encrypted using DES key, which now both Alice and Bob have access to in order to encrypt/decrypt data).

11Security Matters Security of RSA The security of RSA relies on the fact that there are no known algorithms for quickly factoring a number (n), into the primes p and q. If one knew p and q, then given e, one could then easily compute the secret key d. It is not known whether or not there exist fast algorithms for factoring a number, and in this sense the security of RSA is not guaranteed.

12Security Matters Authentication ap 1.0 ap 2.0 ap 3.0 ap 3.1 ap 4.0 ap 5.0

13Security Matters Authentication ap 1.0 –Alice announces to Bob, “I am Alice.” Trudy could have sent this message. ap 2.0 –Alice announces to Bob, “I am Alice”, and asks Bob to authenticate her by matching source IP (in IP header) with Alice’s IP. Trudy could have sent this message if she had done IP spoofing.

14Security Matters Authentication ap 3.0 –Alice announces to Bob, “I am Alice”, and asks Bob to authenticate her by verifying her plaintext password. Trudy may have already eavesdropped earlier, and have stolen Alice’s plaintext password during an earlier conversation between Alice and Bob. Now, Trudy could send the message, “I am Alice” by using Alice’s plaintext password. ap 3.1 –Alice announces to Bob, “I am Alice”, and asks Bob to authenticate her by verifying her encrypted password, which is kept the same for different communication sessions between Bob and Alice. Same disadvantage mentioned in ap 3.0 still exists. Note that Trudy need not decrypt the password. She could still eavesdrop, steal encrypted password, and then perform a “playback attack” on Bob.

15Security Matters Authentication ap 4.0 –Alice announces to Bob, “I am Alice.” –Bob sends a plaintext nonce (= r) to Alice. Note that nonce is a one time value that is specific to that communication session. It is not repeated again in another session. So “playback attack” is not possible. –Alice resends same nonce back to Bob but this time nonce is encrypted with symmetric key used by Alice and Bob. –Bob decrypts nonce using symmetric key. If decrypted nonce equals the nonce he sent Alice earlier (i.e. decrypted nonce = r), then Alice is authenticated. –However, this implies that Alice and Bob must have decided upon and exchanged their symmetric key.

16Security Matters Authentication ap 5.0 –Alice announces to Bob, “I am Alice.” –Bob sends a plaintext nonce (= r) to Alice. Since nonce is a one-time value, “playback attack” is not possible. –Alice resends same nonce back to Bob but this time nonce is encrypted with Alice’s private key. –Bob decrypts nonce using Alice’s public key. If decrypted nonce equals the nonce he sent Alice earlier (i.e. decrypted nonce = r), then Alice is authenticated.

17Security Matters Exchanging Public Keys Why should public key be publicly available? Wouldn’t it be better for Alice and Bob to exchange their respective public keys via , after authenticating each other? –Due to possibility of “man (woman) in the middle attack.”

18Security Matters Man (Woman) in the Middle Attack Alice transmits, “I am Alice.” Trudy (alias Eve) eavesdrops. Bob sends a nonce = r. Trudy intercepts nonce, and sends Bob encrypted nonce (encrypted using her private key). Bob sends a message to Alice asking her for a public key. Trudy intercepts message, and sends Bob Trudy’s public key. Bob decrypts nonce with Trudy’s public key (thinking that he is using Alice’s public key), and inadvertently authenticates Trudy. While Bob is encrypting new data using Trudy’s public key, Trudy is busy posing as Bob to Alice. In particular, –Trudy transmits Bob’s nonce to Alice –Alice transmits encrypted nonce (encrypted using Alice’s private key). –Trudy intercepts encrypted nonce, and asks Alice for her public key. –Alice sends her public key

19Security Matters Man (Woman) in the Middle Attack Bob sends encrypted data (encrypted using Trudy’s public key) Trudy decrypts using her private key, and finds out Bob’s plain text. Trudy encrypts Bob’s plain text using Alice’s public key. Trudy transmits encrypted text to Alice. Alice decrypts using her private key, and finds out Bob’s plain text. Alice and Bob are happy that they have had a secure communication. They are ignorant of the fact that Trudy has intercepted and decrypted Bob’s message to Alice.

20Security Matters Public Key Certification PK cryptography – possible for two entities to exchange secret messages without having to exchange secret keys. Communicating entities have to exchange public keys (without being subject to “man in the middle attack”). Binding a public key to a particular entity is typically done by a Certification Authority (CA).

21Security Matters Certification Authority A CA verifies that an entity is who it claims to be. After verification, CA creates a certificate that binds the public key to appropriate entity. Certificate – includes a public key – includes globally unique identifying information about owner of the public key –Is digitally signed by CA

22Security Matters Digital Signatures and Message Digests Assume Bob wants to digitally sign a “document,” m. Bob’s digital signature could be K B - (m) Due to complexity of RSA, digital signatures are applied to “fingerprints” instead of being applied to message m. Fingerprint – H(m) – where H denotes a “hash algorithm” Bob’s digital signature is K B - (H(m))

23Security Matters Message Digests Message Digest (Hash) algorithms: –MD5; SHA-1; SHA-224;-256;-384;-512 Secure Hash Algorithm is a U.S. federal standard Required for use whenever a secure message digest algorithm is required for federal applications Produces a 160-bit message digest. Longer the output length, the more secure SHA-1 SHA-224, SHA-256, SHA-384, and SHA-512, (which despite the similarity of names), are actually fairly different algorithms to SHA-1 and have much wider safety margins.

Management’s Role in Security A framework to help managers understand that security rests on three cornerstones

25Security Matters Three Cornerstones Technology Organization Critical Infrastructure –Management should provide strong leadership in all three areas.

26Security Matters Cornerstone: Technology Have an understanding/appreciation of technology –Firewalls –IDS/IPS systems –Antivirus/Security Patches –Physical security –Client/Server/Perimeter Security; Secure VPNs –Evaluation of potential technology acquisitions based on their impact on security –Symmetric and Public Key Cryptography

27Security Matters Example: DDoS attack on iPremier Company IPremier –Sells luxury and rare high priced items on Internet –Survived dot com implosion –Customers have good credit history with high spending limits –Experienced a DDoS on Web Server –Ha Ha Ha! s received by Help Desk Problems at Colocation facility: Qdata iPremier employees could not get access to Qdata’s Network Operations Center (NOC)

28Security Matters Questions About Qdata: Although an early entrant in the industry, Qdata lost any prospect of market leadership Had not been quick to invest in advance technology Had experienced difficulty in retaining qualified staff Questions: –If you were the CIO, how would you react to this situation? –What implications does this situation have for the iPremier company?

29Security Matters iPremier Example (Continued) Unable to determine extent of damage (firewall penetrated? How deep is the penetration?) Unable to determine if customer data was stolen (CIO’s main immediate concern) Unable to track (in a reasonable time frame) where ‘Ha, ha, ha’ s received by “support” folks are originating –Even if is tracked eventually – leads to another “Zombie

30Security Matters iPremier’s Response to Attack: Very Poor Try to shut down traffic from “Zombies” – didn’t work – for every zombie that was shut down – two new zombies joined the “party” automatically Shut down Web Server? Cost of downtime?

31Security Matters Imperative Need for Secure Communication Cost of downtime

32Security Matters Unable to determine if they should “disconnect the communication lines” initially CIO and CTO had discussion - may lose logging data that could help them figure out what happened (preserving evidence to find root cause of problem; and what to disclose publicly); later concluded that detailed logs have not been enabled Unable to determine if they should call “Seattle Police” or “FBI”? iPremier’s Response to Attack: Very Poor

33Security Matters How to handle PR (before info about security breach leaks out)? Unable to decide if all systems need to be rebuilt Worst is over? Damage has been done? Attack stopped after about 75 minutes – without any intervention from iPremier or from Qdata! FBI Calls iPremier? Would system rebuild imply wiping out any remaining proof of iPremier’s innocence? iPremier’s Response to Attack: Very Poor

34Security Matters Some Business Implications for IPremier Web server unavailable to legitimate customers Cost of downtime? Bad reputation for the business Lost customers Loss of customer goodwill Legal issues if customer data was compromised

35Security Matters Some Business Implications for IPremier Impact on stock price Unknown damages to the network/business? What if there was another attack?

36Security Matters Cornerstone: Organization Organizational characteristics – typically under the control of organization –Structure –Business environment –Culture –Policies and Responses –Standard Operating Procedures –Education, Training, and Awareness

37Security Matters Management’s Role in Security Realize that total/perfect security is a myth Act appropriately, recognizing that security rests on three cornerstones Critical Asset Identification Initial Risk Assessment Risk Assessment as a continuous process

38Security Matters Management’s Role in Security Creating a security team Initiate and actively participate in planning/design/documentation/ testing of security policy Actively involved in establishing standard operating procedures

39Security Matters Management’s Role in Security Developing and maintaining an appropriate organizational culture Ensure employees are educated and trained regarding importance of following security policy Have an understanding of what each security tool proposed by IT team can do or cannot do

40Security Matters Management’s Role in Security Have a good control environment –Physical controls –Data/Content control –Implementation control (outsourcing) –Operations/Administrative Control –Application Controls specific to individual system components/applications (e.g., Limiting attachments)

41Security Matters Cornerstone: Critical Infrastructure Infrastructure that are so vital that their damage or destruction would have a debilitating impact on the physical or economic security of the country –Telecommunications –Banking –Energy

42Security Matters Why should government/academic institutions/industry collaborate? In each other’s interest CI in large part is owned by the private sector, used by both private and public sectors, and protected in large part by public sector. Need to discuss problems and exchange ideas and solutions to cyber attacks/misuse Resource/cost/information sharing Opportunity to play a role in the evolution of “best practices” Help shape legal and government policies in areas of mutual concerns; Appropriate guidance for rapid additional protection measures

43Security Matters CERT Source: / /

44Security Matters What does CERT do?

45Security Matters Imperative Need for Secure Communication Reported Security Incidents up to 1995 Source: CERT.ORG

46Security Matters Reported Security Incidents 1995 – 2003 Source:

47Security Matters Why have cyber attacks been on the rise? Some reasons

48Security Matters Management’s Role in Security Recognize that security requires an end-to-end view of business processes Achieve a balanced approach to security – one that does not solely focus on technological solutions Recognize that security is a socio- technical issue, and requires strong leadership from management

49Security Matters Management’s Role in Security Management ties everything together Responsibility Ownership Technology Infrastructure Organization Management Security is a Mindset, not a service. It must be a part of all decisions and implementations.

50Security Matters Apply the Dutta/McCrohan framework and help iPremier’s management react appropriately to the security incident.