This Idea was inspired by another (linked).
First consider a sports bra with wide shoulder straps, which can be fairly comfortable, and also is removed only by pulling it over the head. Next consider panties, which can be fairly comfortable, and also are removed by pulling them toward the feet.
Consider connecting them. One way (more about this in a bit) might be to consider a cord that zigzags between them, all the way around the torso. They cannot now be removed unless the cord is removed. What if the bra, panties, and cord were made of Kevlar, or synthetic spider silk, or something equally tough, and locked together? Any man intending to commit rape is going to have a problem!
If a man controls the lock, then this could be a modern version of a "chastity belt". It probably would not be allowed in most modern cultures. If the woman controls the lock then she is in control of sexual access to her body.
In a category on high-tech gadgets, we can consider a lock that is voice-controlled, and it would be tuned to the woman's voice, of course. She would pick whatever pass-phrase she wanted, to unlock the lock. It could also be a very convenient recording device, a witness to things said before (and after) the lock is unlocked.
Now we have to consider a final point, which is the fact that the previously-suggested cord is difficult to remove quickly when one wants to remove it quickly, such as when using a restroom. A relatively simple modification of the overall device is in order.
So, if there was a waist-ring to which the cord from the bra was permanently attached (removed with bra over the head), and if the waist-ring was perhaps zippered all around the torso to the waist of the panties, and the zipper was locked, then that would allow the panties to be removed reasonably quickly when needed.
We might imagine the incidence of rapes in public toilet stalls to increase if this Invention became widely popular. However, remember that voice recorder built into the lock.... If it used electronic memory to store say a week of voices, before beginning to overwrite the saved data, then the woman would have plenty of time to psychologically recover enough, after a rape, to submit the data to the police.
In case of battery failure, the high-tech lock will need an old- fashioned key as a backup plan.-- Vernon, Jul 03 2016 Inspiration Waist_20Chain_20With_20Consent_20LockAs mentioned in the main text. [Vernon, Jul 03 2016] This could be worked round by chopping bits off until they use the voice control, by recording the voice control phrase and by destroying the underwear. Also, I think a week is a bit of an underestimate,-- nineteenthly, Jul 03 2016 I thought it was briefs that won't ride up.-- FlyingToaster, Jul 03 2016 [nineteenthly], I mentiond "Kevlar or synthetic spider sikl" specifically to make it difficult to "work around by cutting bits off". And the woman doesn't need to fully recover from a rape, to recover enough to report it. Finally, while a recording of the pass phrase could work to unlock the lock, that wouldn't turn off the sound recorder...so what other sounds are on the recording, that might back up the claim of rape?-- Vernon, Jul 03 2016 I think the underwear will be incinerated or dissolved in acid by that point.-- nineteenthly, Jul 03 2016 And those are things an average rapist typically carries around?-- Vernon, Jul 03 2016 I often try to think of extremes and then work towards more plausible other options. I'm also conflicted on this. It interests me as a piece of technology, conceptually as it were, but it places the effort required primarily on someone who shouldn't be having to make that effort owing to not being responsible. I mean, I do like it as a practical device, but I'd like to add some kind of response idea which places the onus on potential perpetrators in some way and parodies the idea. Right now I haven't got the imagination to get that together though.-- nineteenthly, Jul 03 2016 / I thought it was briefs that won't ride up. / The Invasion of Dadbag?-- bungston, Jul 06 2016 // [nineteenthly], I mentiond "Kevlar or synthetic spider sikl" specifically to make it difficult to "work around by cutting bits off". //
Cutting bits of the woman off, though? I thought that was implied by // until they use the voice control //.
Another workaround: The rapist could just push the bottom part of the panties to one side. Even if the edges are reinforced with Kevlar or similar, the flesh they encircle is flexible and squishable.
(Or, of course, the attacker could just go for a non- penetrative sexual assault. But your idea didn't claim to defend against that, so that's not really a fair criticism.)
And I agree it somewhat puts the onus to prevent rape on the wrong side. It could even fuel victim-blamers: "You weren't wearing Vernon's Anti-Invasive Underwear! Are you sure you didn't want it?" But it could still be useful, and I too think it's an interesting application of technology. And good on you for trying to do something about it.-- notexactly, Jul 19 2016 It won't work [+]-- Voice, Jul 19 2016 random, halfbakery