CS 472

Assignment #3

Due Midnight, Thursday Oct 27, 2011

 

Message Digest   has many applications among which are Encryption  &  Message Authentication.

Uses sha1 to encrypt & authenticate a message M:

 

1.     Choose a message M of length n*40 characters, where n is at least 2.

2.     Choose a  password P, encrypt  it with  cs472PublicKey.pem  to produce a file: P.base64

3.     Use P  and sha1 to generate a onetime pad M.pad  of the same  size as  M.

4.     xor M.pad  and M to produce a  file:  M.base64

5.     Compute the message digest of P|M|P using  sha1 to  produce a file: M.digest

6.     Use tar  to produce a file: loginA3.tar  containing:

 

README   P.base64   M.base64   M.digest

 

Submit  loginA3.tar  to cs472 under assignment  #3.