CS 772

Assignment #3

Due Midnight, Thursday Oct 25, 2012

 

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

In this assignment use sha1 to decrypt & authenticate a message M.

 

I have used a password P to generate a onetime pad of the same  size as  M and

xored   with M to produce M.cipher.

 

Use the following files to read the message M:

1.     P.base64 is the encryption of P using cs772PublicKey.pem

2.     M.base64 is the base64 encoding of M.cipher.

 

Which of the following is the correct base64 encoding of the message digest of P|M|P  :

a)    MAC1.base64

b)   MAC2.base64