user127090: With BIP 350 a new version of witness is introduced.
Take these two address from the mainnet:
bc1pmfr3p9j00pfxjh0zmgp99y8zftmd3s5pmedqhyptwy6lm87hf5sspknck9 and bc1qmfr3p9j00pfxjh0zmgp99y8zftmd3s5pmedqhyptwy6lm87hf5sstpn3we.
These two addresses has the same witness program. Does this mean they have the same owner ?

user208: It depends.
In general, this isn't the case. It could that this holds true for hypothetical witness versions that could be introduced in the future.
However, it is not true specifically for P2WSH (the bc1q address you posted) and P2TR (the bc1p address you posted). In fact, if you ever see two such address, it is almost certainly the case that one is unspendable.

P2WSH programs encode a SHA256 hash of a script.
P2TR programs encode the X coordinate of a (possibly, and likely) tweaked public key.

It is unfathomably unlikely that someone could find a public key they have the private key for, whose X coordinates match the hash of a script they know and can spend.

127090: <p>With BIP 350 a new version of witness is introduced.</p>
<p>Take these two address from the mainnet:</p>
<p>bc1pmfr3p9j00pfxjh0zmgp99y8zftmd3s5pmedqhyptwy6lm87hf5sspknck9 and bc1qmfr3p9j00pfxjh0zmgp99y8zftmd3s5pmedqhyptwy6lm87hf5sstpn3we.</p>
<p>These two addresses has the same witness program. Does this mean they have the same owner ?</p>
 208: <p>It depends.</p>
<p>In general, this isn't the case. It could that this holds true for hypothetical witness versions that could be introduced in the future.
However, it is not true specifically for P2WSH (the <code>bc1q</code> address you posted) and P2TR (the <code>bc1p</code> address you posted). In fact, if you ever see two such address, it is almost certainly the case that one is unspendable.</p>
<ul>
<li>P2WSH programs encode a SHA256 hash of a script.</li>
<li>P2TR programs encode the X coordinate of a (possibly, and likely) tweaked public key.</li>
</ul>
<p>It is unfathomably unlikely that someone could find a public key they have the private key for, whose X coordinates match the hash of a script they know and can spend.</p>
