Symmetric-Key Cryptography

Statements tagged with the symmetric-key area. This is a generated view, not a home directory – a statement can belong to several areas at once. See all statements for the full index, or the schema for what each column means.

Status	Statement	Tags
	Constant-round Luby–Rackoff, quantum Open for every round count: whether some constant number of Luby-Rackoff rounds with random round functions is indistinguishable from a random invertible permutation against quantum queries in both directions. Four rounds are refuted by a known quantum attack, and the source reports that the published proof of the weaker forward-only four-round claim is flawed. 6 open	otherequivalenceresearch-opennew-idea (ai)
	Erasing real-or-random vs Boneh–Zhandry Open: whether erasing real-or-random security implies Boneh-Zhandry security. The reverse non-implication is proved only in the quantum random oracle model, and this direction is one of six non-implications the source paper conjectures and does not prove. 5 open	standardseparationresearch-opennew-idea (ai)
	6-round Feistel indifferentiability Whether 6-round Feistel is fully indifferentiable from a random permutation is open, bridging the proven r=5 attack and the proven r>=8 construction. 2 open	othertight-boundresearch-opennew-idea (ai)
	Generalized mirror theory The fully generalized Mirror Theory bound for arbitrary cycle-consistent multi-graphs up to the information-theoretic limit is open; current techniques only reach component size O(N^{1/4}). 2 open	standardlower-boundresearch-opennew-idea (ai)
	Logarithmic independence implies PRP Open at independence order log n. The same implication is refuted at order 4 and at every constant order by an explicit construction; the logarithmic-order form is untouched, and no unconditional proof of it can be expected. 5 open	standardcharacterizationresearch-opennew-idea (ai)
	One erasing challenge vs many embedding learns Open: whether a single erasing two-ciphertext challenge query, with classical learning queries, implies security against polynomially many embedding-model superposition learning queries. One of six non-implications the source paper conjectures, and on its own account the one that would close the most remaining cells. 5 open	standardseparationresearch-opennew-idea (ai)
	Standard real-or-random vs embedding two-ciphertext Open: whether one standard-oracle real-or-random challenge query implies one embedding-model two-ciphertext challenge query, with classical learning queries on both sides. Both notions are singleton classes in the source’s classification, and this is one of six non-implications it conjectures. 5 open	standardseparationresearch-opennew-idea (ai)
	OWFs are black-box helpful for CRHFs Open in both directions. Two relaxations — distributional and class-reduction helpfulness — are proved conditional on the Simon-oracle amplification conjecture; neither yields the universal auxiliary primitive the full statement needs. 5 open	otherseparationresearch-opennew-idea (ai)
	3-way collision, oblivious sequential curve Open: closing the factor-root-S gap between the proved oblivious lower bound and a matching table-and-hunt algorithm for finding a 3-way collision with an oblivious sequential branching program. 2 open	romtight-boundresearch-openadaptation (ai)
	Censoring can only hurt Open. The censored side is proved at essentially optimal round count with matching lower bounds; what is missing is the transfer of any such bound to uncensored AES at the same round count. 5 open	standardlower-boundresearch-opennew-idea (ai)
	Tight \(k\)-collision time-space tradeoff The exact tight time-space tradeoff for k>=3 collisions under preprocessing is open; only the k=2 case has a matching upper and lower bound. 2 open	romtight-boundresearch-opennew-idea (ai)