Vanitysearch starts with a seed which, if not specified by the user, is generated randomly. It proceeds from there searching sequentially. If you use the same seed, you will get the same results.
It's perfectly secure to do this. Searching this way creates an infinitesimal bias in the keys that are selected (the selected key is more likely to be found after a long run of non-matches than after an immediately prior match) but even where an attacker knows the exact prefix searched for the bias is extremely tiny-- because nearly spaced solutions are extremely unlikely to begin with-- and not exploitable (because you can't search only keys that meet that criteria... since the criteria itself requires generating the pubkeys to check).So its kind of pointless to try to find a address with this if you don't know seed. What exactly is the search space when searching with vanitysearch is it 2^160 or 2^96?
