Block & Transaction Version numbers about sia HOT 2 CLOSED

*blocks are versioned and nothing else is. v1 txns don't go in v2 blocks, etc.

from sia.

I'm starting to have second thoughts about versioned blocks. Even versioned transactions don't make so much sense as they used to.

Instead you'd want versioned components of everything, which increases the maximum capability of the old nodes after a soft fork. I'm still fully wrapping my head around the best way to do this.

But basically, you want some flags that you can set in the inputs and outputs (aka version number) that indicate they will always be accepted by the node. Then you can soft-fork from "always accepted" to "only accepted under X and Y conditions". Since old nodes will still treat them as "always accepted", the old nodes will keep a database that is semi-compatible, and will still recognize every spend that happens and keep a proper list of unspent outputs.

Then the miners just refuse any transactions that don't fit under X and Y conditions. The old nodes will accept the block, but since >51% of the hashing power is refusing the blocks, the old nodes will be brought to a correct state of affairs because the longest fork will refuse all transactions that are no longer valid after the soft fork.

from sia.