Quote from: BlackHatCoiner on Today at 12:35:15 PM

You still have almost 2²⁵² different combinations.

Minor correction: If you have 4 possibilities for one character in a 64 character private key, then the total number of possibilities is 2²⁵⁴. If you knew for certain one character in the key, then you would have 2²⁵² possibilities.

Quote from: BlackHatCoiner on Today at 12:35:15 PM

There may be addresses like this one: 1111111111111111111114oLvT2 that have no private keys that unlocks them.

Another correction: This address does have a private key. In fact, it has many. It is just that nobody knows what any of them are (or at least, as far as we know nobody knows what any of them are). That address is generated from a RIPEMD-160 of:

Code:

0000000000000000000000000000000000000000

Any private key which produces a public key, which when hashed with SHA-256 then RIPEMD-160 produces the above number, would be able to spend coins at that address.