Post-quantum transactions that require only 96 bytes on-chain: @will_wjk (Imperial College) et al. published a very interesting variant of Shielded CSV, called Compact Shielded CSV. I've always thought the CSV model is attractive in a PQ setting: the blockchain only stores the nullifier, so miners don't have to verify a signature before it gets into a block. Compact Shielded CSV goes a step further: the on-chain nullifier carries no signature at all, only what they call a "degriefer". Pre-quantum that's more than Shielded CSV's 64 bytes, but post-quantum it's much less. Unlike Shielded CSV, which operates on top of Bitcoin, Compact is its own blockchain. That matters for the degriefer: a Compact miner who includes a nullifier with an invalid degriefer can't claim the block reward. Shielded CSV could adopt the degriefer, but on Bitcoin there is no such penalty. Anyone who sees your nullifier before it's confirmed can front-run it with bogus copies for ~100 bytes of fees each, and your spending proof then has to show for every one of them that it's invalid. This is something we deliberately avoided in the design of Shielded CSV. With PQ signatures as large as they are, it probably is a reasonable trade-off. Compact also never discusses reorgs, which are a significant part of the Shielded CSV design. Integrating the degriefer into Shielded CSV would require combining it with the existing reorg handling.