[0] http://www.cs.utsa.edu/~wagner/laws/pad.html
<strike>edit to clarify: "unbreakable" is the wrong word, since it could be brute-forced with enough time and energy, like any encryption method.</strike>
yes it is completely unbreakable.
An envelope key is a securely, randomly generated key used to encrypt the large payload. Then the envelope key (much smaller than the payload) can be encrypted using a one time pad.
The result is that the precious bits of encryption provided by the one time pad are used up at a predictable rate.
Guessing the envelope key is more probable than guessing the one time pad key, but that only breaks a single message's encryption.
An attacker can ‘simply’ try all possible keys and use statistics to filter out those that look like natural language.
If the encrypted text is large enough, chances are you will be left with only one plausible plaintext.
Also, AFAIK, we don’t know whether good encryption using a key much shorter than the plaintext, in the sense that an attacker can’t use statistics on the encrypted text to learn something about the key, exists at all.
Regardless, here's what I think are interesting areas in recent crypto:
- Performance improvements in fully homomorphic encryption, starting with Gentry's work in 2009.
- Practical applications of secure multiparty computation, e.g. Dyadic Security and Google's SMC work.
- Non-NIST standards with actual adoption like Curve25519 and Chacha20-Poly1305
- Functional Encryption: http://eprint.iacr.org/2010/543
- Post-quantum crypto like New Hope (https://eprint.iacr.org/2015/1092) and Supersingular Isogenies (http://eprint.iacr.org/2011/506)
- Candidate functions for Multilinear Maps, e.g. https://eprint.iacr.org/2012/610
- Hardware-based secure enclaves like SGX
But methods of gathering entropy can range from a microphone recording a city street to the classic keyboard/mouse.
Both are valid, but not as practical.
Personally I have the OneRNG, an open source usb-stick that gathers entropy by generating RF noise.
There are other devices like that out today.
[0]: https://z.cash/technology/zksnarks.html
[1]: https://en.wikipedia.org/wiki/Non-interactive_zero-knowledge...
[2]: https://z.cash/
Check out the Open Quantum Systems implementation, they've got a suite incorporating a number of quantum resistant algorithms: https://github.com/open-quantum-safe/liboqs
They have the SIDH implementation you mentioned (https://github.com/open-quantum-safe/liboqs/blob/master/docs...), and a test harness for comparing performance.
http://www.stephenwolfram.com/publications/academic/cryptogr...
https://en.wikipedia.org/wiki/ID-based_encryption
"Identity-based systems allow any party to generate a public key from a known identity value such as an ASCII string. A trusted third party, called the Private Key Generator (PKG), generates the corresponding private keys...."
I think it's innovative and a bit of "thinking outside the box". You do need to ultimately trust a 3rd party (same as in PKI or WOT I guess?).
There is a lot of interesting work in privacy preserving databases as well.
