Information System Security Engineering and Management

1
Information System Security Engineering and
Management

• Risk Analysis and
• System Security Engineering
• Homework (2, 3)
• Dr. William Hery
• hery_at_isis.poly.edu

2
GTS System Description

• Poly is going to set up a new, streamlined grade
  and transcript server (GTS). There is already a
  grade database on a secure server (SGDB) that is
  used for entering and maintaining grade records.
  The new server will allow students to
• view grades without directly accessing the SGDB
• generate full transcripts to be sent to grad
  schools and potential employers from Poly in such
  a manner as to have the recipients of the
  transcripts trust that they are authentic.
• For the homework, assume that SGDB is already
  secure, but there will now be a new
  application/server accessing it. Also assume that
  students can access GTS from the Poly intranet,
  or from the Internet.

3
GTS Architecture
SGDB
Poly Intranet
email
Employer Or Grad School
GTS
Internet
Poly Intranet
Student
Student
4
Assets at Risk (HW 2)

• Integrity of the grade database (but this is
  assumed to be a secure system for our purposes)
• Privacy of the student grades
• Integrity of the grades presented to the student
• Integrity of the transcripts sent out (and the
  trust the recipients have in that integrity)
• Availability of the GTS service
• Poly's reputation as a premier institution in
  information security and an NSA COE in IA

5
Threats (HW 2)

• Students who want to do general mischief or
  target specific students
• Outsiders who want to do general mischief or
  target specific students
• Students who want to send a fake transcript

6
Risk Management Approach (HW 2)

• Integrity of the grade database transfer risk to
  SGDB owner
• privacy of the student grades mitigate with
  technology (authentication of user via password)
  accept some risk of stolen password
• integrity of the grades presented to the student
  mitigate with technology (protect GTS system)
• integrity of the transcripts sent out mitigate
  by digitally signing transcripts
• availability of the GTS service mitigate with
  firewall accept some risk of breaking through
  firewall
• Poly's reputation as a premier institution in
  information security mitigate with all of the
  above

7
Systems Engineering First Steps

• Mission Needs Statement
• A system to allow students to securely access
  their grades, and to allow them to have
  authenticated transcripts emailed to prospective
  employers and grad schools.
• CONOPS A student logs into the GTS Server over
  the Internet or Polys Intranet. A user friendly
  GUI allows the student to see which courses they
  have taken and what their grades have been. The
  student can also request a complete transcript be
  emailed to prospective employers and grad
  schools. For security reasons, the GTS will be a
  separate server from the existing, secure grade
  database, the SGDB.

8
System Architecture and Functional Requirements

• Architecture see first slide
• GTS Functional Requirements
• User (student) interface must authenticate user,
  accept user query, format response
• SGDB interface must format grade query, send to
  SGDB, accept response
• Individual grade request
• Complete transcript request
• GTS must be able to create and send authenticated
  transcripts via email

9
Hig Level Security Requirements

• Authentication of Students
• Protect SGDB from attack at SGDB/GTS interface
  (preserve integrity and privacy of the grade
  database)
• Protect all networks from snooping (privacy of
  grades)
• Protect confidentiality and integrity of all
  processing on the GTS server
• Provide a digital signature service to sign
  emailed transcripts from GTS
• Protect GTS from denial of service attacks

10
Revised GTS Architecture With External Security
Components
MyPoly user Password auth.
SGDB
Poly Intranet
Poly Signing Service
email
Employer Or Grad School
GTS
Internet
Poly Intranet
Student
Student
11
Security Requirements Allocation

• Authentication of Students MyPoly User
  ID/Password authentication
• Protect SGDB from attack at SGDB/GTS interface
  Custom interface to prevent attack (application
  firewall)
• Protect all networks from snooping Encrypted
  network links
• Protect confidentiality and integrity of all
  processing on the GTS server Server security
• Provide a digital signature service to sign
  emailed transcripts from GTS Poly Digital
  Signature Service
• Protect GTS from denial of service attacks
  firewalls, secured server