Robust Hyperlinks Cost Just Five Words Each

We propose robust hyperlinks as a solution to the problem of broken hyperlinks. A robust hyperlink is a URL augmented with a small "signature", computed from the referenced document. The signature can be submitted as a query to web search engines to locate the document. It turns out that very small signatures are sufficient to readily locate individual documents out of the many millions on the web. Robust hyperlinks exhibit a number of desirable qualities: They can be computed and exploited automatically, are small and cheap to compute (so that it is practical to make all hyperlinks robust), do not require new server or infrastructure support, can be rolled out reasonably well in the existing URL syntax, can be used to automatically retrofit existing links to make them robust, and are easy to understand. In particular, one can start using robust hyperlinks now, as servers and web pages are mostly compatible as is, while clients can increase their support in the future. Robust hyperlinks are one example of using the web to bootstrap new features onto itself.