# Chain-Key Cryptography IC’s [Chain-Key Cryptography](https://internetcomputer.org/how-it-works/chain-key-technology) enables smart contracts to sign any output data. Omnity leverages Chain-Key to reduce cross-chain costs to the same level as centralized witness-based cross-chain bridges that use TSS (Threshold Signature Scheme) without sacrificing decentralization. Verifying cross-chain messages on the target chain is usually the most computationally intensive and costly part of a trustless cross-chain process. The Omnity Route smart contract signs cross-chain messages, and the target chain contract authenticates them by checking its signature. No extra gas is needed on EVM target chains for msg sender checking. On non-EVM chains, one ECDSA (Elliptic Curve Digital Signature Algorithm) signature verification is still orders of magnitude lower than the most advanced zk-proof verification in terms of gas cost — not to mention on-chain light client verification, which often involves a few dozen or even a few hundred signature checks, plus a Merkle-proof verification. --- # Agent Instructions: Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter: ``` GET https://omnity.gitbook.io/litepaper/ic-enablers/chain-key-cryptography.md?ask= ``` The question should be specific, self-contained, and written in natural language. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.