mimblewimble team mailing list archive

[John Tromp <john.tromp@xxxxxxxxx>]

> Do inputs ever need to be recorded in a block?

Yes; either explicitly as the pedersen commitment, or implcitly as follows
Inputs could be represented compactly in 8 bytes, either as
4 byte block index + 4 bytes output-within-block index,
or as 8 byte entire-output-history index.

> For instance if I just send you an output, a range proof and a kernel
> you could go try to cut-through each member of your UTXO set until the
> kernel set balanced and then delete that UTXO and add the new output
> and kernel. Granted it would be more efficient if I told you which
> UTXO to delete, but that information does not need to be recorded in
> the blockchain.

If you make things too implicit, you invite all kinds of DOS attacks where
you get tricked into wasting resources.

-John