[Usege]: 我无法让spu runtime调用cheetah_mul about spu

[fionser]

• cheetah_mul is not for matmul
• to perform share*private matmul, just turn on this in your config.json file

[YefanWu]

@fionser
thanks for the quick reply. There are some additional questions left.

How can I designate each matrix in the secure matmul functionality to be secret shared or private? For example, could you tell me how the bool variance you mentioned to designate which matrix should be private?

Besides that, I am also curious about the functionality of the protocols implemented in cheetah_mul.cc?

Also, may I ask it that is the following lambda function makes sense for the spu compiler? This is an attempt to designate matrix W to be private, but run it with the spu and just return an awkward result.

def run_on_cpu(X):#X is matrix (k, d)
    d=....#We set the value of d and n here for debug
    n=....
    W = create_random_binary_matrix(d, n)
    return jnp.matmul(X, W)

[fionser]

When experimental_enable_colocated_optimization=True is setting the config file.
Then the input variables will be kept as private first. For example,

client_input = ppd.device("P1")(lambda x: x)(X)
server_input = ppd.device("P2")(lambda x: x)(W)

The X matrix is a private of party 1, and W is a private from the party 2.

Then if doing the matmul jnp.matmul(X, W). For sure, we cannot compute the result X*W in a form of private, but in shared. That means, private X matmul private W gives a shared result X*W

However, doing boolean * boolean in Cheetah might not be a good practice. Basically, the homomorphic encryption we used in Cheetah will introduce 1-bit error at the end of the computation, which should be fine for the fixed-point computation, but not for the Boolean * Boolean operation.

[YefanWu]

@fionser Thanks for the detailed explanation and supervision. I found no other questions left.
I created binary matrices X, W for easier debugging due to the ground truth value of XW can be small.
I didn't realize that the code snippet will execute boolean multiplication instead of what over FM64.
I will check it and I sincerely appreciate your help.