From a technical perspective, is MultiSigna a decentralized exchange utilizing ethereum?

Question

Does anyone know how we would be able to either view the Ethereum blockchain or inspect the code from Multisigna to confirm if it is a true ethereum decentralized exchange?

Source: https://www.multisigna.com/login.php#

This is pulled from their FAQ:

MultiSigna is a market established in the internet that sets in contact users interested in exchanging fiat ($,€) or crypto (Ethereum) currency for Bitcoin and vice versa. MultiSigna role is to offer the proper structure that allows monitoring and managing step by step the exchange process between the users, keeping the seller’s bitcoins in a multisignature address until the seller has received the counterpart ($,€,ETH). In that moment the bitcoins are transferred to the buyer and the buy/sell operation comes to an end. The protocol developed by MultiSigna allows performing those exchanges in a secure and agile way.

Answer 1

From their description, MultiSigna is not a decentralised exchange. Their primary feature is the use of Bitcoin (not Ethereum) multi-signature feature. Bitcoins are put in an escrow from which they can be released if 2-out-of-3 participants (two counterparties + MultiSigna) approve the transaction. For fiat to BTC, it means that BTC is released when there is MultiSigna receives confirmation of fiat payment, and for BTC to ETH, MultiSigna (and not smart contract) checks Ethereum blockchain for the transaction and released BTC. In theory, two counterparties can transact without MultiSigna being in the middle (because together they can authorise the release of BTC), and only involve MultiSigna when some sort of arbitration is required. However, since BTC multisig requires some advanced use and is not a feature in the standard Bitcoin GUI software, it is likely that most users will simply rely on MultiSigna to authorise all the transactions.