the output of 'get_secure_shuffle'

[yimingqincs]

G = Matrix(4, 4, sfix)
G[0][0] = 1
G[0][1] = 4
G[0][2] = 3
G[0][3] = 10

G[1][0] = 2
G[1][1] = 5
G[1][2] = 1
G[1][3] = 11

G[2][0] = 3
G[2][1] = 6
G[2][2] = 2
G[2][3] = 12.1

G[3][0] = 0
G[3][1] = 0
G[3][2] = 0
G[3][3] = 0
permutation = sint.get_secure_shuffle(len(G))
print_ln('permutation: %s', permutation.reveal())

1. when I print the permutation of the matrix, I get permutation: 0. How do I get the correct output of the permutation?
2. G.secure_permute(permutation, reverse=False, n_threads=None), the value of permutation has to be used by output of sint.get_secure_shuffle ? How can I change it?

[mkskeller]

1. The returned value is just a handle. There is no facility to output the permutation itself.
2. Yes. What do you mean by changing it? If you want to change the permutation protocol itself, you would have to do that in the C++ code.

[yimingqincs]

When I use permutation = sint.get_secure_shuffle(len(G)), I want to sort the permutation to get a new one. I can use the new permutation to perform G.secure_permute(permutation, reverse=False, n_threads=None) to get a new matrix

[mkskeller]

You can convert the internal representation to a secret vector representation as follows: k = sint(regint.inc(n)).secure_permute(permutation). k can then be used in sorting.reveal_sort() to permute arrays and matrices.

[yimingqincs]

Thanks for your quick reply! This is helpful for me.

[yimingqincs]

if I perform k = sint(regint.inc(len(G))) to get the k. then I use the k in reveal_sort(k,b) to permute a matrix b = sfix.Matrix(4,4). But I fail to run. Could I perform this?

I want to use the permutation of sorting matrix G to sort other matrix b.

Could you please give me some advice?

[yimingqincs]

G = Matrix(4, 4, sfix)
G[0][0] = 1
G[0][1] = 4
G[0][2] = 3
G[0][3] = 10

G[1][0] = 2
G[1][1] = 5
G[1][2] = 1
G[1][3] = 11

G[2][0] = 3
G[2][1] = 6
G[2][2] = 2
G[2][3] = 12.1

G[3][0] = 0
G[3][1] = 0
G[3][2] = 0
G[3][3] = 0

permutation = sint.get_secure_shuffle(len(G))
G.sort((0,))
k = sint(regint.inc(len(G))).secure_permute(permutation, reverse=True)

when I run above the code, can I get k is the permutaion of sorting G? And then we set the value of matrix b is the same as the value of matrix G.

when I perform reveal_sort(k,b) , I can't get the same permutation between b with G.

[mkskeller]

This is currently not implemented.