Cross-chain dApps function across multiple different smart contracts deployed across multiple different blockchains, while multi-chain dApps are deployed in multiple individual versions across distinct networks.

Some common bridge security vulnerabilities include weak on-chain and off-chain validation, improper handling of native tokens, and misconfigurations. Testing the bridge against all possible attack vectors is recommended to ensure sound verification logic.

Cross-chain interoperability solutions have the potential to significantly improve the efficiency and functionality of blockchain networks by enabling communication, data, and value transfers among different networks.

Orb Labs announced a $4.5M seed round Tuesday, led by Bain Capital Crypto, with participation from Shima Capital, 6th Man Ventures, Aves Lair, Newman Capital, Modular Capital, and SevenX Ventures.

Rainbow Bridge, a cross-chain bridge integrated with the Aurora blockchain, has been fully restored after a temporary suspension likely due to security concerns.

Adam Back (Bitcoin core development team leader, BlockStream CEO) has a sentence that impressed me, "Great design looks very simple, but the process of designing it is extremely complicated". But not all product designs that look simple, like LayerZero, are great.

Synapse (SYN), the native token of the cross-chain Synapse Protocol, is trading at a five-month high of $1.22 following a 44.74% move to the upside over the past 24-hours.

So to summarize, mutichain technology creates an internet of blockchains capable of communicating freely while remaining secure thanks to a shared underlying security layer, while cross-chain technology uses smart contracts to create synthetic versions of your coins that are able to interact with other blockchains directly.

Polkadot has released version 3 of its cross-chain messaging format Cross-Consensus Messaging (XCM), which enhances interoperability between different blockchains in its ecosystem. 

Cross-chain interoperability gives users the freedom to choose how they want to interact with DeFi, without being constrained by any one blockchain network.