I have a question, P = kG, k is in the range of [k1, k2], I am now solving for a public key, but I don’t know the range of [k1, k2], how should I use the kangaroo.exe program, or can I explain how Estimate the range of [k1, k2]?
There is no way to estimate the range. You would have to search range from 000000000000....1 to FFFFFFFFFFF...F (1 to 256) which would be a really long time.