Generalized Mirror Theory Conjecture
Statement: AI-written, not yet formalized. Proof: open – no attempt yet.
View PDF · Download LaTeX source
Abstract
Mirror Theory, initially introduced by Patarin (2003), provides lower bounds on the number of non-degenerate solutions to systems of bivariate linear equations over \(\mathbb{F}_2^n\). While recent breakthroughs (e.g., Cogliati et al., 2023) have rigorously established the theory for component sizes up to \(\xi_{\max} = O(2^{n/4}/\sqrt{n})\), the fully generalized conjecture for arbitrary dependency graphs up to the information-theoretic limit remains an open problem in theoretical cryptography. This page gives a self-contained statement of the open Generalized Mirror Theory Conjecture.
Formal Preliminaries
Let \(V = \{p_1, p_2, \dots, p_q\}\) be a set of variables taking values in \(\{0,1\}^n\), where \(N = 2^n\). We consider systems of bivariate affine equations over \(\mathbb{F}_2^n\) defined on a multi-graph \(G = (V, E)\).
Let \(G = (V, E)\) be a connected graph with \(q = |V|\) vertices and \(m = |E|\) edges. Let \(\lambda : E \to \{0,1\}^n \setminus \{0^n\}\) be an edge-labeling function assigning non-zero target constants to each edge. The system of equations is given by:
\[ \mathcal{E}(G, \lambda) := \Bigl\{ p_i \oplus p_j = \lambda_{i,j} \;\Big|\; e = (p_i, p_j) \in E \Bigr\}. \]
A tuple \((P_1, \dots, P_q) \in (\{0,1\}^n)^q\) is called a valid (non-degenerate) solution to \(\mathcal{E}(G, \lambda)\) if:
- \(P_i \oplus P_j = \lambda_{i,j}\) for all \((p_i, p_j) \in E\).
- \(P_i \neq P_j\) for all \(i \neq j\) (all variables in \(V\) are pairwise distinct).
We denote the set of all non-degenerate solutions by \(\mathbf{Sol}(\mathcal{E}(G, \lambda))\) and its cardinality by \(h(G, \lambda) := |\mathbf{Sol}(\mathcal{E}(G, \lambda))|\).
A system \(\mathcal{E}(G, \lambda)\) is cycle-consistent if for every cycle \(C\) in \(G\), the XOR sum of labels along the cycle evaluates to \(0^n\). Let \(\xi_{\max}(G)\) denote the maximum size (number of vertices) of any connected component of \(G\), and let \(\nu(G) = |E| - |V| + c(G)\) be the circuit rank (cyclomatic number) of \(G\), where \(c(G)\) is the number of connected components.
The Unconditional Generalized Mirror Theory Conjecture
While localized versions of Mirror Theory have been proven for trees and bounded-degree graphs up to \(\xi_{\max} = O(N^{1/4})\), the full asymptotic statement for arbitrary graph topologies up to \(O(N^{1/2})\) or higher query limits remains open.
Let \(G = (V, E)\) be a graph with \(q = |V|\) vertices and \(m = |E|\) edges. Let \(\mathcal{E}(G, \lambda)\) be a cycle-consistent affine system. Assume that \(q \le o(N^{1/2})\) and that the maximum component size satisfies \(\xi_{\max}(G) \le o(N^{1/2})\).
Then, the number of non-degenerate solutions \(h(G, \lambda)\) satisfies the tight lower bound:
\[ h(G, \lambda) \ge \frac{(N)_{q}}{N^m} \cdot \left( 1 - O\left( \frac{q \cdot \xi_{\max}(G)}{N} \right) \right), \]
where \((N)_q = N(N-1)\dots(N-q+1)\) denotes the falling factorial.
Equivalently, for a collection of \(c\) connected tree components \(T_1, \dots, T_c\) with \(|V(T_k)| = q_k\), \(q = \sum q_k\), and \(m = q - c\):
\[ h(G, \lambda) \ge \frac{N^q}{N^{q-c}} \prod_{i=0}^{q-1} \left(1 - \frac{i}{N}\right) \left( 1 - \epsilon(q, \xi_{\max}, N) \right), \]
where \(\epsilon(q, \xi_{\max}, N) \to 0\) as long as \(q \cdot \xi_{\max}(G) = o(N)\).
State of the Art and Theoretical Gaps
| Reference | Scope / Topology | Max Component (\(\xi_{\max}\)) | Status |
|---|---|---|---|
| Patarin (2003), Patarin (2005) | Linear Graphs / Trees | \(\xi_{\max} = O(1)\) | Gaps identified |
| Cogliati & Seurin (2018) | Circle Graphs (\(\nu=1\)) | \(\xi_{\max} = O(N^{1/3})\) | Proven |
| Cogliati et al. (2023) | Arbitrary Forest Graphs | \(\xi_{\max} = O(N^{1/4}/\sqrt{n})\) | Fully Proven |
| Open Conjecture | Arbitrary Multi-Graphs | \(\xi_{\max} = o(N^{1/2})\) | OPEN |
Why the conjecture remains open:
- High-order link deletions: current algebraic techniques (such as link-deletion equations) rely on induction over component sizes. When \(\xi_{\max}\) exceeds \(O(N^{1/4})\), higher-order dependency intersections generate non-trivial error terms that cannot be absorbed without explicit structural cancellation lemmas.
- Multi-cycle dependencies: for graphs with high cyclomatic numbers (\(\nu(G) > 1\)), handling non-equations (\(P_i \neq P_j\)) alongside linear constraints requires tracking exact character sums over non-abelian representations, which currently lack tight lower bounds.
This conjecture is open — no proof exists yet.
Once (an attempt at) a proof exists, add its own .tex source and compiled PDF (e.g. latex/proof.tex / pdf/proof.pdf) and link them here, following the same convention as the statement.
Formal artifact.
Lean statement — autoformalized by Claude Sonnet 5; not yet checked by a human against the tex statement above.
Only the conjecture’s statement has been formalized so far (as a Lean theorem ending in sorry — see lean/Statement.lean), not a proof. Once a proof exists, set status.proof_informal/status.proof_review/status.proof_formal accordingly and regenerate the badge with scripts/status_badge.py.
The conjecture is a statement about a range, not about a single bound: the mirror-theory lower bound is rigorous for small component size, and what is asked is whether the same bound survives as \(\xi_{\max}\) grows into the general multi-graph regime. That shape is why the open obligation below is phrased as a disjunction — extend the technique past the current ceiling, or produce a counterexample — since a failure would most likely appear as a graph whose component structure defeats the counting rather than as a slightly worse constant.
Nothing beyond this has been written here; see the problem page for how this sits among the mirror-theory results.
- Patarin. Luby-Rackoff: 7 Rounds are Enough for \(2^{n(1-\varepsilon)}\) Security (CRYPTO 2003). Where Mirror Theory starts.
- Patarin. On Linear Systems of Equations with Distinct Variables and Small Block Size (ICISC 2005; LNCS, 2006).
- Cogliati and Seurin. Analysis of the Single-Permutation Encrypted Davies-Meyer Construction (2018).
- Cogliati, Dutta, Nandi, Patarin and Saha. Proof of Mirror Theory for a Wide Range of \(\xi_{\max}\) (2023). The rigorous range this conjecture proposes to extend.