Is NIST's public calling:


...for a post-Quantum Cryptographic Algorithm a public calling for a public key distribution method (ex. Diffie Hellman) or a public key encryption method (ex. RSA)?


1 Answer 1


The second paragraph in the link you shared says the following:

It is intended that the new public-key cryptography standards will specify one or more additional unclassified, publicly disclosed digital signature, public-key encryption, and key-establishment algorithms that are capable of protecting sensitive government information well into the foreseeable future, including after the advent of quantum computers.

So it appears that they want both key establishment algorithms (what you refer to as "public key distribution method") as well as public key encryption algorithms (and digital signature algorithms too).

  • $\begingroup$ Thanks Ella, So to recap, if we used something like Regev and Peikert's Learning With Errors (LWE) to exchange a private key which we then used to encrypt data in some new / unclassified way. That would fulfill NIST's public calling requirements, correct? $\endgroup$
    – BL12345
    Nov 23, 2017 at 22:01
  • $\begingroup$ @BL12345 I think they are interested in examining a set of techniques for exchanging a private key, i.e. designs such as LWE and alternatives to it. Basically, they want post-quantum replacements for Diffie-Hellman and RSA. I'm not sure what you're asking, but it sounds like you're taking a pre-established LWE based cryptosystem and tacking on your own novel symmetric encryption mode of operation. If so, I don't think that's what NIST is after, they have a standard technique for what to do after they keys have been exchanged; See point 13 here $\endgroup$
    – Ella Rose
    Nov 24, 2017 at 0:46
  • $\begingroup$ I see now what NIST is after, per point 13: "The AES key will be the symmetric key output by the encapsulate function. (The key generation function will be identical to that for the original KEM, and the decryption function will be constructed by decapsulation followed by AES decryption.)" So it sounds like they will be using AES for the symmetric key portion. You were right to assume my initial intentions were to piggyback on LWE and introduce my own symmetric encryption algorithm (which utilizes DSP to encrypt data in a manner difficult for classical and quantum computers to break). Thanks $\endgroup$
    – BL12345
    Nov 24, 2017 at 3:24
  • $\begingroup$ ...What's even worse is that I spent more than 1 year working on my encryption algorithm, talking to multiple DSP professionals and mathematicians / computer science professionals. To finally get something working and then be told that I wasn't even working on the right problem. Quite the letdown, I must say... $\endgroup$
    – BL12345
    Nov 24, 2017 at 3:31
  • $\begingroup$ @BL12345 Well, with any luck you learned a lot about information theory and some solid engineering principles. Though, I am curious why you would talk to DSP pros and mathematicians instead of cryptographers, general smartness is no substitute for actual experience with a specific subject (maybe cryptographers were just unavailable?). If you came up with a solid principle for defending against a quantum computer you could still write about the technique, you're always free to try and submit papers to arxiv or eprint.iacr (though that may be challenging if you're not an academic). $\endgroup$
    – Ella Rose
    Nov 24, 2017 at 16:43

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