From: Piete Brooks <Piete.Brooks@cl.cam.ac.uk>

We were using ALPHA code when we started ....

I didn't realise that.

(4) is still applicable isn't it ? What tells people to stop, or do they go on for ever ?

A message in a newsgroup, a mailing list, or a web page. Even if you can mount a denial-of-service against this, it will only make people continue the search uselessly. It won't prevent you from finding the key.

...

The main drawback of the random search is that the expected running "time"

where "expected" is some loose average .....

Nope. It's what I get when I do the math (basic probability theory) to find the expected running time. But I could be wrong. I'll try to write it in TeX and put it on my web page.

...

I suspect that sequential searching from a random starting point would be much worse in the case of many independent searchers.

Convince me (please) ....

That would be hard because I've been thinking about it, and I'm less and less convinced myself.

...

In conclusion, I think random searching is the way to go. It has its advantages -- yes. Did you use it for Hal1 ? :-))

No, but I had few machines and fast connections (and even then, I did have some network problems). But if you think sequential searching can work, let's do it. I don't think we have to worry about deliberate attacks for the moment, and the factor of two is significant. My previous message was based on the assumption that it would be hard to get rid of the server overload. Maybe we should use random searching as a fallback mode in case of network problems. It cannot hurt, except that it makes the programs more complex. -- Damien