Introduction

The following projects assume a PKI infrastructure. However, an alternative to PKI could be used. (PGP, GnuTLS, ...)

Shared secret (symmetrical) keys could also be an alternative.

The following projects requires the exchange of keys, certificates, etc. The class could use a local store (web server, LDAP directory, thumb drive, ...) so students could exchange the necessary information for testing.

PKI Certificate Authority

OpenSSL could be used as the class PKI infrastructure (Certificate Authority).

Use OpenSSL As A Class PKI Certificate Authority

Links to OpenSSL Information

Python and OpenSSL

PyOpenSSL Documentation
How to sign data using OpenSSL with Python
Python OpenSSL Examples

Project #1

Create functions to encrypt and decrypt a line of text input by the user.

Create a program to display the encrypted/decrypted text.

Use another users public encryption key to encrypt the line of text. Verify the encryption by sending the line of text to the other uses.

Project #2

Create functions to digitally sign a line of text input by the user.

Create a program to display the text's digital signature.

Verify the digital signature by sending the line of text and digital signature to another user.

Project #3

Create functions to encrypt and decrypt a file selected by the user.

There are two aspects to the problem:

• The file is for the user's use (encrypted/decrypted by the user)
• The file is to be encrypted and sent to another user
  (The use encrypts the file and the other uses decrypts the file.)

Send the file to another user to verify.

Project #4

Create functions to digitally sign and verify a file selected by the user.

Assume the file is signed and sent to another user. The other use would:

• Determine who sent the file
• The file was not modified after being signed

Project #5

Create functions to authenticate a user. (Assume the function is used to authorize the user access to sensitive data.)

Notes:

• The projects are to be demonstrations and not a complete infrastructure.
• Students could exchange public keys for demonstrations and testing
  • USB drive
  • Download them from a class web site¹ where the keys are maintained
• The secure distribution and maintenance of keys should be emphasized as a problem for a security infrastructure

¹A class web site could be another project.