Ronin, a cryptocurrency network revealed a breach where threat actors swept $540 million worth of Ethereum and USDC stablecoin. The attack is one of the biggest in the history of cryptocurrency cyberattacks, particularly retrieved funds from a service called Ronin Bridge. Pulled-off attacks on "blockchain bridges" have become normal in the last two years, the Ronnie incident is a testimony to thinking hard about the problem. Blockchain bridges (network bridges) are apps that allow users to transfer digital assets from one blockchain to another.
Cryptocurrencies can't usually interoperate, for instance, one can't do a transaction on a bitcoin platform via doge coins, hence, these "bridges" have become an important process, in the cryptocurrency world. Bridge services use 'cryptocurrency' to convert a bitcoin into another. For instance, if one goes to a bridge and uses a different cryptocurrency, like bitcoin (BTC), the bridge splits out wrapped Bitcoins (WBTC). In simple terms, it's similar to a gift card or a check that shows stored value in an open alternative format.
Bridges require a vault of cryptocurrency coins to underwrite the total wrapped coins, and that trove is the primary target for threat actors. "Bridges will continue to grow because people will always want the opportunity to join new ecosystems. Over time, we'll professionalize, develop best practices, and there will be more people capable of building and analyzing bridge code. Bridges are new enough that there are very few experts," says James Prestwich.
Besides the Ronin heist, hackers stole around $80 Million worth of cryptocurrency from the Qubit bridge in January, around $320 Million from the Wormhole bridge in February, and $4.2 Million a few days later from Meterio Bridge. Another thing that one should note is that Poly network had around $615 Million worth of cryptocurrency stolen in August last year, but the attackers returned the fund a few days after. "Ronin was created by the Vietnamese company Sky Mavis, which develops the popular NFT-based video game Axie Infinity. In the case of this bridge hack, it seems attackers used social engineering to trick their way into accessing the private encryption keys used to verify transactions on the network," reports the Wired.
