是否建议加密url参数而不是使用纯文本？

Question

I've had another developer pose the possibility of combining and encrypting/obsfucating all the parameters to pages for php, as a security measure against manipulations via crafted urls and to prevent interior knowledge of the database (e.g. knowing the id in the database of a specific entry).

In other words, instead of single or multiple public query parameters like ids, there would be a single encrypted blob that would be decrypted server-side, and re-encrypted when links are crafted.

Are there problems with this approach? Are there substantial advantages that make it worthwhile? Is this approach used in the wild to good effect?

Answer 1

You should design your system to prevent unauthorized access. Obsfucating (useful encryption on data the client generates is not a possibility) is not a worthwhile defense.

For instead, instead of giving the user a database ID, given them a hash (with perhaps a session seed) of the ID. The 128bit+ search space of the hash and (for reasonable DB sizes) low probability of collisions would be a much better approach. You could also encrypt the ID on the server for values the client never needs to manipulate (with a seed) but make sure it has the same properties as the hash I mentioned—namely that the search space is very large compared to the possible value space.