How does the ZKsync bridge work?

Could you elaborate on the mechanics of the ZKsync bridge? How does it facilitate the transfer of assets between the Ethereum mainnet and the ZKsync network? Is it a secure and efficient process? What are the key components that make up this bridge, and how do they interact to ensure seamless transactions? I'm particularly interested in understanding the role of zero-knowledge proofs in this process and how they contribute to maintaining privacy and security.