feat: add SECURITY.md

Author: yi-sun

README.md

@@ -41,4 +41,8 @@ If you want to import the verifier contract into your own repository for testing
 
 ## Audits
 
-You can find the audit reports for these contracts in the [OpenVM repo](https://github.com/openvm-org/openvm/tree/main/audits).
+Versions v1.1 and later of these contracts are recommended for production use. The code to generate these contracts from release commits of OpenVM was [audited](https://github.com/openvm-org/openvm/blob/main/audits/v1.1.1-cantina-report.pdf) by [Cantina](https://cantina.xyz/) in April 2025.
+
+## Security
+
+See [SECURITY.md](SECURITY.md).

SECURITY.md

@@ -0,0 +1,5 @@
+# Security Policy
+
+## Report a Vulnerability
+
+Contact [[email protected]](mailto:[email protected]).