I have come up with an encryption algorithm and I am looking for a place to possibly publish it. Any ideas?
First, and I know this isn't exactly the answer you're seeking, but I'd mull over it for a while. Hopefully you have read Schneier's Memo to the Amateur Cipher Designer; it speaks the truth.
In short, before you try to go the route of publishing your algorithm, here are some things you should consider:
- What makes your scheme compelling to study? Is it more secure or more efficient than already-existing schemes like AES, Salsa20, Sosemanuk, ...? Is it interesting from a theoretical point of view? Does it solve some heretofore difficult problem? If none of these things, you might have difficulty generating interest in it.
- What analyses have you done already? Does your scheme exhibit proper diffusion, e.g. does it possess a good avalanche effect? Do you have some proof of security contingent on the difficulty of another cipher/problem? (This is often not the case for encryption schemes, but it could have such a thing.) Have you verified that your scheme resists common cryptanalytic techniques like differential and linear cryptanalysis?
- Are you prepared to justify everything in your design? And I do mean everything: cryptographers want to know details. Why did you do this, why did you do that, how did you generate those constants, could the constants be better? Why not improve on your design in such-and-such maybe-or-maybe-not-obvious way? How's your scheme's efficiency? Good, bad? Does the security level it provides justify its efficiency?
- Who else has looked at your scheme? What are their credentials? Like Schneier says, anyone can make a cipher they themselves cannot break; the real test is having others try.
That said, you might already have considered all of these things and more, in which case I apologize profusely. Supposing you have, where can you publish it?
If you're more amateurish and looking for general community input, I'd pick somewhere like the /r/crypto subreddit and maybe try to hang around some other crypto-related spots on the web. If you're related with a university in some way, you might be able to track down cryptology researchers at yours, depending on your position and so forth.
If you're talking about more prestigious academia-related spots, I'd go with one of the IACR publications, where a great deal of cryptography papers are published. For general preprint hosting, almost all papers are submitted (at some point or another) to the Cryptology ePrint Archive, also ran by IACR. If you're familiar with academia, this is an arXiv-esque site for cryptology specifically.