In defense of cryptocurrency
&quot;transaction reversibility is not about the ledger, but rather about the transaction rules that a currency uses. A reversible currency requires that someone anoint this trusted party (or trusted parties) and that they use their powers to freeze&#x2F;burn&#x2F;transact currency in ways that are at odds with the recorded owners’ intentions. And indeed, this is a capability that many tokens now possess&quot;<p>I think this is arguing that reversibility is not antithetical to permissionless blockchains, because reversibility can be implemented on top of permissionless blockchains.<p>But that doesn&#x27;t answer the critique -- the critique is that most real world systems do need trusted parties, and if you build a system of trusted parties on top of a permissionless blockchain, then you could have saved a lot of complexity, risk, and proof-of-economic-waste burn by building on top of a permissioned distributed ledger instead. Reversibility is one example of a design requirement that undoes the claimed advantages of permissionless blockchains that are meant to justify their inherent downsides.