Coin Selection and Output Design

Coin Selection and Output Recommendations

Inputs:

1. Pick single large output that is slightly larger than send value: a: If possible create 1 - 1 transaction with remainder being a reasonable fee. b. If change output needed, try to create a round-value output that is at-least 10x the fee. c. If change would be less than 10x fee, try to find a larger input to spend.

If large input is more than 2x amount to be spent: a. Try to create two outputs of identical amount: (i) spend (ii) change, and fee. b. If fee too large create 3 outputs: (i) spend (ii) change (iii) small change round value, and fee.

Change:

In General: Never create a small change output if it would increase the required fee by more than the output's value.

Privacy: Avoid small outputs in general. Just spend to fee.

Privacy: Try to create change outputs with round-value outputs, adjust fee to have non-round value.