Need Help with Recovering SOL Sent to an Off-Curve Address

Question

I recently encountered a peculiar issue where I mistakenly sent SOL to a slightly incorrect wallet address. Upon verifying the transaction on Solscan.io, I realized that the destination address is marked as "off-curve" (isOnCurve: False), indicating that it doesn't align with the cryptographic standards of valid Solana addresses. This seems to imply that no private key exists for this address.

Here are the specifics of my situation:

• The transaction was intended for a known address, but due to a single character error, it went to a different, off-curve address.
• The transaction was confirmed on the blockchain, and the funds now appear in the history of the unintended address.
• Based on my understanding, an off-curve address should technically not be able to receive or hold funds since it does not correspond to a valid public key.

My questions to the community are:

1. Why was this transaction processed if the destination address is invalid? Shouldn't the blockchain reject such transactions to non-compliant addresses?
2. Is there any conceivable method or protocol on Solana that could allow for the recovery of the funds sent to an off-curve address?
3. What steps can be taken to prevent such occurrences in the future, and are there any ongoing discussions about improving address validation in wallet software or at the protocol level?

I appreciate any insights or suggestions you might have. This experience has been quite troubling, and I hope it can spur some discussion on safety measures and error checking in our transactions.

Thank you in advance for your help and guidance.

Answer 1

To answer your questions:

1. Off-curve addresses are used for program-derived addresses, so they are actually usable and valid in Solana. For example, all associated-token-accounts are off-curve addresses, and can hold SOL. More info at https://solana.com/docs/core/pda
2. In your case, you would need to break sha-256 to recover your funds. If you broke sha-256, you would have way more power than just recovering your funds though!
3. Since these addresses are acceptable at the protocol level, the only thing that can be done is better validation by wallets, and perhaps a mechanism that forces users to send small amounts to a new address in order to confirm it's correct, similar to current retail banking systems.

I'm really sorry for your loss.