Stealth Address Scanner

• In this project, we customize the ergo scanner project to find and store ergo boxes related to a stealth address. This project is based on Ergo blockchain scanner

you can read the scanner document here.

What is Stealth Address?

According to "Kushti":

Another solution for improving privacy is using stealth addresses. A stealth address preserves recipient privacy without per-transaction interaction needed (so receiver published an address e.g. on its website, and then sender can obtain some unique one-time address from it). This could be useful for privacy-preserving commerce, private donations and crowdfunding campaigns etc.

In other words, a stealth address is used when you want to hide your exact amount of entrance. you can pass a public key to people and they compile a stealth contract and send some Ergs to the contract address. On the other hand, the receiver can prove the contract and collect the Ergs.

• If you want to know more about the stealth address maybe this post be helpful.

We customize the stealth contract like this

 val stealthScript: String = {
   s"""{
      |  val gr = decodePoint(fromBase64("GR"))
      |  val gy = decodePoint(fromBase64("GY"))
      |  val ur = decodePoint(fromBase64("UR"))
      |  val uy = decodePoint(fromBase64("UY"))
      |  proveDHTuple(gr,gy,ur,uy)
      |}
      |""".stripMargin

As you can see we put the variables in the contract, unlike the introduced methods. This decision brings us to some benefits and some costs.

• As a benefit, we can use the address of compiled contract in the wallet and do the payment very easily.
• As a benefit, our contract is so simple and we can use it in any transactions e.g. you sell some SigUSD and send the Ergs to this contract.
• As a cost, the contract address is no longer fixed and every time will be changed and it makes some problems for the receiver to find the boxes.

We do some experiments and study and find a pattern based on the ergo tree of a stealth address box to scan them on the ergo network. So we customized the ergo scanner project to find stealth boxes and store them in the database. Also, develop some APIs to simplify the user's work.

This project has a simple UI to generate a new stealth payment address base on the given public key (AKA. stealth address) the stealth address contains two parts:

stealth:pk(in base58 format)

the prefix part helps up to use this feature in the wallets easily and makes it a standard to use everywhere.

In the UI part after you enter the stealth address you can get the stealth payment address and a QRCode. also by clicking the address you can copy it to the clipboard.