Super-Encryption

[Ben Laurie]

mlong at bridgetonconsulting.com wrote:
> Sender's Algorithm
> 
> SymmetricKey1 = 3DES_IV1, 3DES_Key1
> Cipher1 = 3DES_Encrypt(message)
> Digest = SHA1(message)
> RSA_Key1 = RSA_Private_Encrypt(Digest || 3DES_Key1)
> 
> SymmetricKey2 = 3DES_IV2, 3DES_Key2
> Cipher2 = 3DES_Encrypt(Cipher1)
> RSA_Key2 = RSA_Public_Encrypt(3DES_Key2)
> 
> 
> Receiver's Algorithm
> 
> 3DES_Key2 = RSA_Private_Decrypt(RSA_Key2)
> Cipher1 = 3DES_Decrypt(Cipher2)
> 
> Digest || 3DES_Key1 = RSA_Public_Decrypt(RSA_Key1)
> message = 3DES_Decrypt(Cipher1)
> 
> Compare Digest with SHA1(message)

I don't see any value added by cipher1 - what's the point?

Cheers,

Ben.

-- 
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