As i know, generally nowadays hybrid protocols are more widely used than either symmetric or public key cryptosystems separately. I read that public key system is used to exchange and share secret via insecure channel so that the key is then used in symmetric cipher.
Also, there is otp, which is unbreakable as its information-theoretic security system. This is such a strong notion of security. However, we are all aware that it has its own drawbacks.
Recently an idea popped up randomly in my head - could we use one time pad instead of, say, AES, once the key is shared via public key? I'm sure that it is unpractical. However, only issue i see rn is requirement of same length key. But could we stretch it?
If we consider that somehow key stretching could be done properly, would there still be any other reason to not use otp and stick with standart symmetric algorithm?
- is length requirement only issue in this kinda system?
- couldnt we compromise speed a bit (during stretchin) for in return getting such a strong notion of security, making computation irrelevant?
- couldnt we not even take away AES part but rather put otp in between as another layer? (note that since there'd be stronger notion it could in return reduce low bound of AES key size)
- could otp be considered as security by obscurity - hence very nice reason to not use it?