The “liberal marketing” unleashes a debate on the essence of self -ocustody in Bitcoin

Wallet of Satoshi, a bitcoin purse for mobile devices announced on July 1 its spark launch, a second layer of bitcoin that is interoperable with lightning network and gives access to a spectrum of financial applications.

The launch is in a private beta phase and is promoted as an event that returns Bitcoin’s complete self -ocustody through light to the US market. But This launch has not been exempt from controversies, Since some users say that Spark, being a stathain and conserving one of two fragments of a private key, does not allow true self -ocustody. Kevin Hurley, creator of Spark, went out of criticism explaining his security model.

According to Lightspark’s blog, this is a light chain on Bitcoin ideal to house financial apps and launch assets in Bitcoin. «Designed for payments and liquidations, SPARK allows developers to transfer bitcoin and Bitcoin native assets (including stablecoins) instantly, with a practically null cost, without losing the connection with the Bitcoin infrastructure. All natively in Bitcoin, without bridges or encapsulation, ”explains the documentation.

With this infrastructure added to their purse, the users of Satoshi Wallet They will be able to make payments using BTC and Stablecoins, both for Spark and Lightning Network.

The announcement in social networks aroused the controversy by a certain Bitcoiner sector, which considers that Spark promotion could include deceptive advertising. Matt Corallo, a well -known Bitcoiner developer, comments that it is “shameful to call this ‘autocustody’ when you fully trust that the operator will not steal your money. Words mean things, and self -ocustody communicates to users that no third can do something that results in the theft of their money. This [Wallet of Satoshi en Spark] It’s not that, ”says Corallo.

The developer explains that Spark is a Statechain, which has a security model that needs a degree of confidence. As Cryptonotics reported, Statechains are a Bitcoin scalability solution that allow UTXO spending (unused transaction outputs) outside the main bitcoin chain.

The Statechains They use multifirma transactions (Multisig) 2 of 2 signatures, where one of the signatories is the Statechain entity; Spark, in this case. The critic of Corallo refers to the fact that, as a holder of one of two firms, Spark is a Statechain, which requires confidence and does not allow true self -system.

An researcher exhibited a practical example of how Statechains work and what is their nature:

«A stathain is a multifirma 2 of 2: Alice deposits in Statechain. She has custody. The operator cannot steal. Alice sends her private key to Bob. The Statechain entity now has a shared key with Alice and Bob. The stathain can collide with Alice and make a double expense to Bob’s funds. To not do this, Statechain must eliminate the shared key with Alice. If the stathain does, Bob has the immediate custody of the funds. Bob can never know if the state chain was really honest. They can only know when they withdraw funds from the state chain or when they become difficult. Upon receiving funds, you have custody in case the established operator is honest. You can trust that they are honest, but you can never be sure.

@januszg_, independent researcher.

Giacomo Zucco, another important developer, clarifies that in a Statechain like Spark, the coordinator cannot steal money from having a key fragment. What it can is, as a possessor of one, conspire with the previous owners of the UTXO to appropriate the funds. Even so, Zucco considers the announcement of Wallet of Satoshi in Spark a case of “marketing too liberal.”

Kevin Hurley, creator of Spark, emerged in the controversy to explain his security model, which he says is even more transparent than that of Lightning Network. He comments that the statement that, when using Spark, you must “trust your operator, your money will not steal your money is not true.”

«Spark is based on N operators 1 (or a configurable minority threshold) to be honest only at the transfer point. If they are honest at that time, that means that this operator correctly eliminated the key. If they do, even if they are hacked or decide to become malicious in the future, they cannot do anything to affect their funds. If users decide not to trust any of the operators, they are free to leave unilaterally at any time and the operators do not have the ability to censor them or prevent them from doing so. It is a model that compares very favorably with practically everything else that exists ».

Kevin Hurley, creator of Spark.

The official documents of the SPARK security model ensure that the network operates under a “momentary” trust model, implying that trust is required when executing the transaction, After which the operator discards the key automatically. “Whenever at least one (or a configurable threshold) of Spark operators behaves honestly during a transfer, the system guarantees optimal safety forward,” says Spark.