[gopalv]

> The server only has to send one bit back to the client!

As much as the example is a bad one because it leaks server-side info to an unauthenticated client, I've had scenarios where if you have > 3 ssh keys in your key-chain all ssh login attempts fail after 3 keys are tried & cause failures. I end up writing ~/.ssh/config entries; a lot of them for the client to remember which key to try first.

My favourite real-life bloom-filter story is the "unsafe URLs" list that is in Chrome - the "Safe Browsing Bloom" is a neat way to send out obscured information about the bad URLs without actually handing out a list to a user. The web URLs or domains which find a match in this, do need to be checked upstream, but it avoids having to check for every single request with a central service.

On a similar note, been playing with a variant of bloom filters at work called a Bloom-1 filter [1] which works much faster than a regular bloom filter which has a lot of random memory access for 1 bit reads.

[1] - https://github.com/prasanthj/bloomfilter/blob/master/core/sr...