Resource Sharing of Portable Computers Using Wireless Communication

1. Resource Sharing of Portable Computers Using Wireless Communication By Christine Meyer

2. Outline • Routing Protocols • Load Balancing Techniques • Cluster Computing Software • Wireless Security Attacks • Conclusion

3. Wireless Adhoc Mode Peer-to-Peer Communication

4. Wireless Infrastructure Mode Communication through Access Point

5. Direct Sequence Spread Spectrum (DSSS)

6. Wireless Range

7. Routing Protocols • Dynamic Source Routing (DSR) • Destination Sequence Distance Vector (DSDV) • Temporary-Ordered Routing Algorithm (TORA) • Ad Hoc On-Demand Distance Vector (AODV)

8. Comparison of Routing Protocols Packet Delivery Ratio Routing Overhead

9. Diffusive Load Balancing on Domain

10. Windows Management Instrumentation Namespace:root\WMI for signal strength root\CIMV2 for LB information

11. Cluster Computing Software Server Display Manager Resource Manager Client Job Manager Client Manager Application

12. Wireless Network Display

13. Client to Server Routing 1 Routing A Routing A Client A Server Client B

14. Client to Server Routing 2 Routing to Server Client A Routing A, B Server Routing A, B Client B

15. Encryption using Java import javax.crypto.*; import javax.crypto.spec.*; import java.security.*; SecretKey key = KeyGenerator.getInstance("DESede").generateKey(); byte[] keyBytes = new byte[] {107,127,4,115,-23,55,93,47, -36,-105, -26, 4, 38, -83,-29, 62, 107,127,4,115,-23,55,93,47}; try { SecretKey key = new SecretKeySpec(keyBytes, "DESede"); Cipher ecipher = Cipher.getInstance("DESede"); ecipher.init(Cipher.ENCRYPT_MODE, key); // Seal (encrypt) the object s1 = new SealedObject(mat1, ecipher); s2 = new SealedObject(mat2, ecipher); } catch (Exception e) {}

16. Decryption with Java byte[] keyBytes = new byte[] {107,127,4,115,-23,55,93,47, -36,-105, -26, 4, 38, -83,-29, 62, 107,127,4,115,-23,55,93,47}; try { SecretKey key = new SecretKeySpec(keyBytes, "DESede"); Cipher dcipher = Cipher.getInstance("DESede"); dcipher.init(Cipher.DECRYPT_MODE, key); // Unseal (decrypt) the class a = (Matrix)s1.getObject(dcipher); b = (Matrix)s2.getObject(dcipher); } catch (Exception e) {}

17. Java Transformation String • Algorithm • AES, Blowfish, DES, DESede, RSA, RC2, RC4, RC5 • Mode • None, CBC (Cipher Block Chaining), • CFB (Cipher Feedback Mode), • ECB (Electronic Codebook), • OFB (Output Feedback Mode), • PCBC (Propagating Cipher Block Chaining) • Padding • No Padding, • PKCS5Padding • SSL3Padding • Default: DES/CBC/PKCS5Padding (64 bits to 128 bits) • DES 64 bits to 64 bits: • transform = "DES/ECB/NoPadding“

18. Passive attacks to decrypt traffic Access Point Destination Packet 1 XOR Packet 2 = Plaintext Eavesdropper

19. Active attack to inject new traffic Access Point Destination RC4(X) XOR X XOR Y = RC4(Y) Eavesdropper

20. Active attacks to decrypt traffic Decrypted Message Decrypted Message Access Point Internet Eavesdropper’s Computer Encrypted Message Eavesdropper

21. Table based Attack Access Point Destination Eavesdropper Table of IV and Key Streams

22. WPA Denial of Service Attack WPA can shutdown the system if it receives two failed packets within a one-second period Wi-Fi Encryption Fix Not Perfect http://www.wired.com/news/business/0,1367,56350,00.html

23. Conclusion • It is possible to improve performance through resource • sharing of portable computers • In the future, the transfer rate for wireless will be • greater therefore reducing transfer time • Security is provided for access points but not for • ad-hoc mode • Encryption is possible through Java with a small • overhead factor