Technical Seminar Presentation 2004 GOURAV PODDAR IT [1] DATA SECURITY IN X.25 NETWORKS Advisor: Mr. Anisur Rahman

Technical Seminar Presentation 2004 GOURAV PODDAR IT [2] DATA SECURITY IN X.25 NETWORKS INTRODUCTION X.25 : An ITU-T protocol for WAN Communication. User to Network Interfacing (UNI); DTE – DCE Interface. Many channels share one physical connection. Security mechanism: Data Encryption for secrecy Data & Entity Authentication for preserving Data Integrity

Technical Seminar Presentation 2004 GOURAV PODDAR IT [3] DATA SECURITY IN X.25 NETWORKS X.25 Network Devices DTE – Data Terminal equipment DCE – Data Circuit-terminating Equipment PSE – Packet Switching Exchange PAD – Packet Assembler / Disassembler

Technical Seminar Presentation 2004 GOURAV PODDAR IT [4] DATA SECURITY IN X.25 NETWORKS X.25 Network Device Operation

Technical Seminar Presentation 2004 GOURAV PODDAR IT [5] DATA SECURITY IN X.25 NETWORKS Virtual Circuits Virtual Call Two Types of Virtual Circuits: Switched virtual circuit (SVC): Phone call Permanent virtual circuit (PVC): Leased lines Up to 4095 VCs on one X.25 interface

Technical Seminar Presentation 2004 GOURAV PODDAR IT [6] DATA SECURITY IN X.25 NETWORKS X.25 Protocol Suite PLP – Packet Layer Protocol LAPB – Link Access Procedure – Balanced X.21bis Protocol

Technical Seminar Presentation 2004 GOURAV PODDAR IT [7] DATA SECURITY IN X.25 NETWORKS Threats to Data Security in X.25 Passive Wiretap : Tapping into the carrier medium and reading the data. Active Interference : Modification of Data during transmission.

Technical Seminar Presentation 2004 GOURAV PODDAR IT [8] DATA SECURITY IN X.25 NETWORKS Security Requirements Operational Secure Key Management Approval

Technical Seminar Presentation 2004 GOURAV PODDAR IT [9] DATA SECURITY IN X.25 NETWORKS X.25 Security Problem The Key Management Problem General Layer 6 and 7 Layer 3

Technical Seminar Presentation 2004 GOURAV PODDAR IT [10] DATA SECURITY IN X.25 NETWORKS Basis of Solution Unit Unique RSA Keys Key Encrypting Keys (KEKs) Data Encrypting Keys (DEKs)

Technical Seminar Presentation 2004 GOURAV PODDAR IT [11] DATA SECURITY IN X.25 NETWORKS Fast RSA Processing Completely automated key management across the network Relies on RSA for the secure mechanisms Reliant on RSA co-processor in each crypto unit Power to perform a 512-bit RSA decryption under a second

Technical Seminar Presentation 2004 GOURAV PODDAR IT [12] DATA SECURITY IN X.25 NETWORKS CONCLUSION Developed to overcome the problems inherent in transmitting the data over low quality copper wires. Ensured reliable transmission of data over WAN with supported speed of up-to 56 Kbps. Added overhead and processing imposed on the transmission to achieve high level of reliability was a drawback. But still remains cost effective and viable alternative for low speed connectivity among many locations.

Technical Seminar Presentation 2004 GOURAV PODDAR IT [13] DATA SECURITY IN X.25 NETWORKS THANK YOU !