<p>If every node on the Bitcoin network was a pruned node, I believe it would not be possible to start new nodes or to recover a wallet from a seed phrase or from a backup file (e.g. of a wallet.dat without chainstate data).</p>
<p>I guess that Kaspa prunes its directed acyclic graph (DAG) of blocks in a way that preserves the ability of a new node to build and verify a UTXO set from the remaining data. After reading the description you linked to, it isn't clear to me how this is safely done. I doubt it could be applied to Bitcoin.</p>

CC BY-SA 4.0
2024-04-20T10:36:09.703Z
2024-04-20T10:42:17.657Z
2024-04-20T10:42:17.657Z
RedGrittyBrick
<p>There are <a href="https://kaspa.org/features/" rel="nofollow noreferrer">some Proof-Of-Work chains</a> where pruning is default on their nodes, i.e. the network does not rely on full unpruned nodes at all:</p>
<blockquote>
<p>Due to the pruning mechanism, Kaspa nodes only needs ~3 days of prior history to be stored by each decentralized machine.</p>
</blockquote>
<p><strong>1.</strong> Do Kaspa <a href="https://eprint.iacr.org/2018/104.pdf" rel="nofollow noreferrer">rely on additional assumptions</a> that Bitcoin do not rely on in order for such prunning to work?</p>
<p><strong>2.</strong> How do Kaspa nodes construct their utxo set in such circumstances?</p>
<p>Who is to verify the signature</p>
<p>Lets imagine that some time in the future due to some reason (be it high cost of storage or due to protest against on-chain inscriptions) everybody node on a Bitcoin network is a pruned node. In that circumstances and within current Bitcoin protocol:</p>
<p><strong>3.</strong> Would it be possible to start a new node from scratch. Would it possible to verify a the last 550 mb of blocks without having a connection with even one full, archival node.</p>
<p><strong>4.</strong> With a node that was just started from scratch, would it be possible for such a node to construct the UTXO set in which there would be some utxos that were created below the blockheight of the chop off point.  As far as I know, the utxo set is constructed by each node based on the data in the blocks (and not synced with other nodes as it is the case with blocks) - correct me if I am wrong.</p>

<synchronization><pruning><utxo-set><utxo-committments>
Would it be possible to sync a new node without it being connected to even one unpruned node?
John Smith
# Would it be possible to sync a new node without it being connected to even one unpruned node?

(Asked by: username_0 on 2024-04-20)

There are [some Proof-Of-Work chains](https://kaspa.org/features/) where pruning is default on their nodes, i.e. the network does not rely on full unpruned nodes at all:

> Due to the pruning mechanism, Kaspa nodes only needs ~3 days of prior history to be stored by each decentralized machine.

**1.** Do Kaspa [rely on additional assumptions](https://eprint.iacr.org/2018/104.pdf) that Bitcoin do not rely on in order for such prunning to work?

**2.** How do Kaspa nodes construct their utxo set in such circumstances?

Who is to verify the signature

Lets imagine that some time in the future due to some reason (be it high cost of storage or due to protest against on-chain inscriptions) everybody node on a Bitcoin network is a pruned node. In that circumstances and within current Bitcoin protocol:

**3.** Would it be possible to start a new node from scratch. Would it possible to verify a the last 550 mb of blocks without having a connection with even one full, archival node.

**4.** With a node that was just started from scratch, would it be possible for such a node to construct the UTXO set in which there would be some utxos that were created below the blockheight of the chop off point. As far as I know, the utxo set is constructed by each node based on the data in the blocks (and not synced with other nodes as it is the case with blocks) - correct me if I am wrong.

**Tags:** synchronization, pruning, utxo-set, utxo-committments


---

## 1 answers

### Answer by username_1 on 2024-04-20. Score: 1 | Accepted answer

If every node on the Bitcoin network was a pruned node, I believe it would not be possible to start new nodes or to recover a wallet from a seed phrase or from a backup file (e.g. of a wallet.dat without chainstate data).

I guess that Kaspa prunes its directed acyclic graph (DAG) of blocks in a way that preserves the ability of a new node to build and verify a UTXO set from the remaining data. After reading the description you linked to, it isn't clear to me how this is safely done. I doubt it could be applied to Bitcoin.


---

