Ten Reasons why a Paper is Rejected from a Crypto Conference

The paper doesn't use TeX.

The authors do not understand the question. For example they claim to construct a block cipher but the construction is not even stateless. Or the paper does not mention what the algorithm is supposed to achieve (is this an encryption algorithm ?).

The paper does not provide any security analysis; or the paper only considers exhaustive search.

The paper does not provide a security proof when such proof would be required. A publickey protocol based on lower level crypto primitives must have a security proof, based on a well defined notion of security; otherwise it is basically useless.

There is no comparison with the state of the art. For example the paper proposes a stream cipher that is 1000 slower than existing ones.

The approach conflicts with a known impossibility result (which is never mentioned in the paper). The easiest case is an information theoretically secure encryption scheme with a key shorter than the message.

The paper cryptanalyzes itself. The paper mentions an attack against a previous version of the algorithm that still applies to the new version.

The paper makes claims without proofs. The authors claim to have a polynomial time factoring algorithm but they do not provide the factorisation of any large integer; or the proof is postponed to an ``extended version'' of the paper.

The paper uses a technique that was proven many times unsuccessful in the cryptographic literature (e.g., ``chaos functions'') but the authors do not explain why their approach is better.

Finally, the techniques used in the paper do not seem to apply to the problem at hand, which makes the result difficult to believe. For example the paper tries to factor N=pq by writing it as a set of binary equations over the bits of p and q. Or the authors try to use cellular automata to build a publickey encryption scheme.
This list was inspired by Scott Aaronson's
Ten Signs a Claimed Mathematical Breakthrough is Wrong.