Suppose I know that the private key for the public (32 bit) 0209c58240e50e3ba3f833c82655e8725c037a2294e14cf5d73a5df8d56159de69 is in the range of 1-50 bits, can I run a script with an unknown bit size in the range of 1-50?
The Pollard-Kangaroo script from
this message seems to find keys even when the specified bit size doesn't match the key mask, but it does take longer. I guess the bits parameter is a hint at where to start searching, rather than a maximum search space limit.
For example, both of these runs will find key #32 (b862a62e)
pollard_kangaroo.py
34 0209c58240e50e3ba3f833c82655e8725c037a2294e14cf5d73a5df8d56159de69
pollard_kangaroo.py
30 0209c58240e50e3ba3f833c82655e8725c037a2294e14cf5d73a5df8d56159de69