Monero and Zcash are the only major currencies where you can reuse addresses

sgp_

Monero and Zcash are the only major currencies that provide safe payments for institutions. Let me explain in a way you may not have heard of before:

It's really common for institutions to require that funds be sent to a whitelisted address, not to any other address.

The process of receiving a new address, verifying that it's accurate and owned by the intended recipient, and then adding to software whose aim is to prevent accidental spends is cumbersome and prone to risk.

For transparent coins, institutions need to decide between the safety/convenience of reusing addresses or the privacy of not reusing addresses. Most choose the former (notice your exchange deposit address usually doesn't change).

For Monero and shielded Zcash, institutions and users can be provided a single address. Since these addresses never appear on the blockchain, they get the best of both worlds: the safety and convenience of reusing addresses, and the privacy of not associating these transactions together.

I really want to stress that for above, it HAS to be SHIELDED Zcash. Zcash generally, including the more-common transparent addresses, do not have these protections at all. Most institutions only support transparent addresses, but that seems to be slowly changing.

Besides hiding addresses on-chain, how could this be addressed? Theoretically it can be solved with more sophisticated wallet software that safely exchanges information, but this is far more complex and is a far worse solution to an unnecessary problem.

Monero and (shielded only) Zcash solve real issues that institutions and individuals have today, all with no worse user experience or extra integration effort. Sometimes privacy allows for everything to be simpler, even if that's not the primary intent of these features 🙂

Original source is my Twitter:
https://twitter.com/JEhrenhofer/status/1324418841754148864

mcstanky

This is also true for Pirate chain (ARRR) since it is based on Zcash code and enforces Z addresses (shielded) by default. Although ARRR probably isn’t considered a "major" currency (yet).

shengchalover

That’s not factually true. For example, the Reusable Payment Codes — the evolutionary descendants of bitcoin's stealth addresses (just like Monero addresses are) — can be published online as a single address (a payment code) and payers will calculate unique ephemeral address for each payment. This definitely does not provide privacy by itself as payee could combine all the utxos and reveal the payments, but combined with some caution and mixing protocols (e.g. CashShuffle) or other privacy protocols (e.g. as in Zcoin) quite reasonable level of privacy could be archived in any transparent utxo-based blockchain.

sgp_

shengchalover this is definitely possible, but as far as I'm aware, no one has built out support for this. Note that custody providers and institutions try to harmonize processes for as many assets as possible. Whitelisting addresses works for nearly all coins. Doesn't mean it won't happen, but it somewhat breaks their workflows (though less so than a new manual exchange of address would).