Can bookmarklets store configuration data?

As I understand, bookmarklets are executed with the origin of the page, where they are invoked. While this is pretty much the very reason they are useful, it limits the ability of the bookmarklet to keep state.

Specifically, I want to store configuration data for a bookmarklet. A use-case would be e.g. allowing persistent site-independent customization of the behaviour, without changing the code.

Additional criteria would include

• Protecting bookmarklet configuration from unwanted access by other bookmarklets
• Sharing bookmarklet cofiguration with trusted other bookmarklets
• Protecting bookmarklet configuration from possible malicious websites.

An extreme example would be a bookmarklet syncing content with a third-party file hosting service like Dropbox, which would require securely storing an authentication key.

Is there any such possibility?

Additional notes

• I am primarily using iOS to add behaviour on iOS and Windows. The iOS-part prevents the use of browser extensions (which anyway would limit portability).
• I am trying to use bookmarklets specifically because I don't have access to a server, so some techniques used in bookmarklets related to webservices don't apply.

Possible Workarounds I thought of

• Configuration might be put in the bookmarklet manually, e.g. by hosting the main javascript on a public service like github, and creating a proxy bookmarklet that loads it with #-options, e.g.

  javascript:function runBmlet(url){ var s=document.createElement("script"); s.src=url; document.head.appendChild(s); }; runBmlet("http://url.of/my/script.js#DropboxData=YOURDATAHERE");
  

  which is however much less convenient on the long run than storing the configuration in something akin to localStorage.