Topic: Are there practical application of blind signatures? (Read 106 times)

Yes, it's even stated as one of application on BIP 340. See https://github.com/bitcoin/bips/blob/master/bip-0340.mediawiki#user-content-Blind_Signatures. Many Bitcoin CoinJoin protocol also use blind signature.

Blind signatures are used in the ZeroLink coinjoin protocol and in Chaumian ecash mints. The first is non custodial, the second is custodial.

Signing a transaction using a private key is a practical way of proving that a particular transaction is authorized by someone. Inorder to verify the authenticity of that signature, the corresponding public key is required. This has been my only understanding of digital signatures until I came across Blind Signature earlier today.

From what I could gather, blind signatures was invented by David Chaum(popular cryptographer), and it's also a form of digital signatures that contain hidden messages, before they are signed and broadcasted. I am not really sure of why blind signatures was invented or what it's trying to achieve, but I think "Confidentiality" has something to do with it.

We all know Bitcoin transactions are pseudonymous and not anonymous, which means our transactions can be monitored but not traced to our real world identities. Every transactions are stored on the Blockchain as a record, which means the coins are not practically moving from one wallet to another.

I am not sure if there are practical applications of blind signatures in Bitcoin transactions, as it sounds odd to me for someone to initiate a message (transaction input) that is hidden.

So my questions are:
1. Are blind signatures applicable to Bitcoin transactions?
2. If yes, how do we view them on the Blockchain?. I would appreciate a convincing example.

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I am 100% open to correction as I still see myself as a learner. Pardon any of my error and share your personal opinion. You might want to also DYOR after reading this.