On Chrome’s developer page about storage in extensions, it explicitly says that the storage area is not encrypted, so confidential information should not be stored there.
Safari offers a “SafariExtensionSecureSettings” class to securely store key/value pairs. Is there an equivalent in Google Chrome?
There is currently no equivalent in Google Chrome to Safari’s “SafariExtensionSecureSettings”.
Here is another answer that outlines security in localStorage more generally https://stackoverflow.com/a/3719435/117068