How does Blom's scheme work? Is the polynomial expression of it a normal one?
A few additional questions:
- How big does the prime modulus need to be? Can it be bigger than the size of the derived key?
- The implementation used by HDCP 1.x uses addition and no multiplication in the calculation of the shared key. Simple examples I've seen in handouts for courses at universities posted online include multiplication as well. Why the discrepancy?
- Does the scheme require any special operations like those used in finite field arithmetic?
- What is the term for the scheme? Is it a key establishment scheme, a key agreement scheme, a key exchange scheme, etc.
- This is the first scheme for key agreement that I've seen that doesn't rely on Diffie-Hellman or public key cryptography. Are there any other alternatives?