Ranges and will it work for any Pub Key?

[Mahuro]

Hi there,

I have two basic questions:

1- Can anyone give me a brief guide about how to use the ranges in Kangaroo? How to define them, and can you define one large range to find the whole key?

2- most addresses reveal the Pub Key, can we use Kangaroo then to work on any address/pub Key?

Thanks.

[sssergy]

Yes, most Bitcoin addresses do reveal the public key, especially after the first transaction from that address
. The Kangaroo algorithm (Pollard's Kangaroo) is designed to find the private key corresponding to a given public key on the secp256k1 elliptic curve used in Bitcoin
.

However, this algorithm can only be used if it is already known that the private key lies within a certain predefined range
. It is effective for problems with a limited keyspace, such as Bitcoin puzzles where keys are generated within a narrow, predetermined range
. It is impossible to compute the original search range directly from the public key for full-sized 256-bit keys.

For this reason, you cannot define one single, massive range covering the entire possible keyspace (2^256) to find any private key. Such a search is technically and computationally infeasible because the algorithm's complexity, although roughly the square root of the range size, would still be astronomically high for the full keyspace
.

Therefore, programs like BSGS or Kangaroo are applicable only to public keys that were pre-generated within a known, relatively small range, as is done in various Bitcoin puzzles.

[Mahuro]

Thank you for your reply. It is clarifying.

[Mahuro]

Do you know, in Linux, how to enumerate the GPUs? I am using this, but getting an error:

./kangaroo -gpu gpuId0,gpuId1,gpuId2,gpuId3,gpuId4,gpuId5,gpuId6,gpuId7 -ws savedKangs.txt -wi 30 in.txt
Kangaroo v2.2

Unexpected gpuId0,gpuId1,gpuId2,gpuId3,gpuId4,gpuId5,gpuId6,gpuId7 argument

Thank !