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Information-Theoretic Deniability and the Forest Analogy

Bilal El Issaoui

Published May 5, 2026• 0 citations
Publisher

Abstract

Information-Theoretic Deniability and the Forest Analogy This paper establishes information-theoretic deniability through a precise structural argument: the Forest Analogy. The central result is a symmetry property showing that an attacker who possesses a valid alibi chain stands in exactly the same position as an attacker who knows only the public parameter N. The verification function cannot distinguish the real authentication chain from any alibi chain. This property holds without cryptographic assumptions — it is information-theoretic, not computational. The authentication chain is built on the linear Diophantine system N = 19A + 9B, in which every number N has approximately N/171 valid representations per layer. A three-layer Matryoshka structure produces a multiplicatively structured search space of approximately 10¹¹² operations. The key insight is that this search space is symmetric: it is equally large and equally unnavigable from outside the system as from within it. Uniform Sampling and the Generation Algorithm Uniform sampling means here that every valid chain — consisting of A, B, a1, b1, a2, b2 satisfying 19A + 9B = N, 19a1 + 9b1 = A, 19a2 + 9b2 = a1, and the digit-root conditions — has exactly equal probability of being generated as the real authentication chain. The generation algorithm achieves this through a hierarchical weighted CDF sampler (cumulative distribution function), operating as follows: 1. The distribution over all valid A-values is computed, where the weight assigned to a given A equals the exact number of valid chains on layers 1 and 2 that can be extended from that A. 2. A is sampled according to this weighted distribution. 3. Given A, the value a1 is sampled in the same manner, with weights determined by the exact number of valid (a2, b2)-pairs beneath that a1. 4. Finally, (a2, b2) is chosen uniformly at random from all solutions to 19a2 + 9b2 = a1. All weights are computed exactly. This hierarchical weighted sampling procedure therefore induces a provably uniform distribution over all complete chains, without requiring the generator to enumerate or store them explicitly. Proposition (Uniform Chain Distribution): Let N be a fixed public parameter. Let Omega(N) denote the set of all valid chains C = (A, B, a1, b1, a2, b2) satisfying: - 19A + 9B = N - 19a1 + 9b1 = A - 19a2 + 9b2 = a1 - and the digit-root conditions on each layer. Then the hierarchical weighted CDF sampler generates each chain C in Omega(N) with probability exactly 1 / |Omega(N)|. Proof. Define the following counting functions: - w2(a1) = |{(a2, b2) : 19a2 + 9b2 = a1, digit-root conditions satisfied}| - w1(A) = sum over all valid a1 of w2(a1), where the sum runs over all a1 satisfying 19a1 + 9b1 = A for some valid b1 - w0 = sum over all valid A of w1(A) = |Omega(N)| The sampler proceeds in three steps: Step 1. A is drawn with probability P(A) = w1(A) / w0. Step 2. Given A, a1 is drawn with probability P(a1 | A) = w2(a1) / w1(A). Step 3. Given a1, the pair (a2, b2) is drawn uniformly with probability P(a2, b2 | a1) = 1 / w2(a1). The joint probability of generating the complete chain C = (A, B, a1, b1, a2, b2) is: P(C) = P(A) * P(a1 | A) * P(a2, b2 | a1) = w1(A) / w0 * w2(a1) / w1(A) * 1 / w2(a1) = 1 / w0 = 1 / |Omega(N)| Since this holds for every C in Omega(N), the sampler induces the uniform distribution over Omega(N). "Remark" B and b1 are uniquely determined once A, a1, a2, and b2 are fixed, via the Diophantine equations. They do not need to be sampled separately. The uniformity therefore holds over all complete chains, including these values. Theorem (Forest Symmetry): Let N be a public parameter and let C = (A, B, a1, b1, a2, b2) be any valid verification chain. Then for every valid alibi chain C': P(C is authentic | verification succeeds, C') = P(C is authentic | verification succeeds) Proof: The verification function evaluates solely against N. By Proposition (Uniform Chain Distribution), every valid chain is generated with identical probability 1 / |Omega(N)|. The alibi C' therefore carries no information about which chain is authentic. Formally, C' and the event "C is authentic" are conditionally independent given that verification succeeds. The posterior probability is thus unaffected by knowledge of C'. The Forest Analogy: The Forest Analogy makes the symmetry precise. The public parameter N is the forest. Each representation (A, B) on layer zero is a tree. Each sub-representation on layer one is a branch. Each leaf is a layer-two representation. All leaves are identical — every chain verifies correctly against N. An attacker holding a valid alibi leaf cannot determine which leaf is the real one, because the verification function provides no distinguishing information. *This work is licensed under CC BY-SA 4.0. Commercial licensing (without ShareAlike) available on request: elissa_oui@outlook.com*

DOI
10.5281/zenodo.20045343

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Information-Theoretic Deniability and the Forest Analogy This paper establishes information-theoretic deniability through a precise structural argument: the Forest Analogy. The central result is a symmetry property showing that an attacker who possesses a valid alibi chain stands in exactly the same position as an attacker who knows only the public parameter N. The verification function cannot distinguish the real authentication chain from any alibi chain. This property holds without cryptographic assumptions — it is information-theoretic, not computational. The authentication chain is built on the linear Diophantine system N = 19A + 9B, in which every number N has approximately N/171 valid representations per layer. A three-layer Matryoshka structure produces a multiplicatively structured search space of approximately 10¹¹² operations. The key insight is that this search space is symmetric: it is equally large and equally unnavigable from outside the system as from within it. Uniform Sampling and the Generation Algorithm Uniform sampling means here that every valid chain — consisting of A, B, a1, b1, a2, b2 satisfying 19A + 9B = N, 19a1 + 9b1 = A, 19a2 + 9b2 = a1, and the digit-root conditions — has exactly equal probability of being generated as the real authentication chain. The generation algorithm achieves this through a hierarchical weighted CDF sampler (cumulative distribution function), operating as follows: 1. The distribution over all valid A-values is computed, where the weight assigned to a given A equals the exact number of valid chains on layers 1 and 2 that can be extended from that A. 2. A is sampled according to this weighted distribution. 3. Given A, the value a1 is sampled in the same manner, with weights determined by the exact number of valid (a2, b2)-pairs beneath that a1. 4. Finally, (a2, b2) is chosen uniformly at random from all solutions to 19a2 + 9b2 = a1. All weights are computed exactly. This hierarchical weighted sampling procedure therefore induces a provably uniform distribution over all complete chains, without requiring the generator to enumerate or store them explicitly. Proposition (Uniform Chain Distribution): Let N be a fixed public parameter. Let Omega(N) denote the set of all valid chains C = (A, B, a1, b1, a2, b2) satisfying: - 19A + 9B = N - 19a1 + 9b1 = A - 19a2 + 9b2 = a1 - and the digit-root conditions on each layer. Then the hierarchical weighted CDF sampler generates each chain C in Omega(N) with probability exactly 1 / |Omega(N)|. Proof. Define the following counting functions: - w2(a1) = |{(a2, b2) : 19a2 + 9b2 = a1, digit-root conditions satisfied}| - w1(A) = sum over all valid a1 of w2(a1), where the sum runs over all a1 satisfying 19a1 + 9b1 = A for some valid b1 - w0 = sum over all valid A of w1(A) = |Omega(N)| The sampler proceeds in three steps: Step 1. A is drawn with probability P(A) = w1(A) / w0. Step 2. Given A, a1 is drawn with probability P(a1 | A) = w2(a1) / w1(A). Step 3. Given a1, the pair (a2, b2) is drawn uniformly with probability P(a2, b2 | a1) = 1 / w2(a1). The joint probability of generating the complete chain C = (A, B, a1, b1, a2, b2) is: P(C) = P(A) * P(a1 | A) * P(a2, b2 | a1) = w1(A) / w0 * w2(a1) / w1(A) * 1 / w2(a1) = 1 / w0 = 1 / |Omega(N)| Since this holds for every C in Omega(N), the sampler induces the uniform distribution over Omega(N). "Remark" B and b1 are uniquely determined once A, a1, a2, and b2 are fixed, via the Diophantine equations. They do not need to be sampled separately. The uniformity therefore holds over all complete chains, including these values. Theorem (Forest Symmetry): Let N be a public parameter and let C = (A, B, a1, b1, a2, b2) be any valid verification chain. Then for every valid alibi chain C': P(C is authentic | verification succeeds, C') = P(C is authentic | verification succeeds) Proof: The verification function evaluates solely against N. By Proposition (Uniform Chain Distribution), every valid chain is generated with identical probability 1 / |Omega(N)|. The alibi C' therefore carries no information about which chain is authentic. Formally, C' and the event "C is authentic" are conditionally independent given that verification succeeds. The posterior probability is thus unaffected by knowledge of C'. The Forest Analogy: The Forest Analogy makes the symmetry precise. The public parameter N is the forest. Each representation (A, B) on layer zero is a tree. Each sub-representation on layer one is a branch. Each leaf is a layer-two representation. All leaves are identical — every chain verifies correctly against N. An attacker holding a valid alibi leaf cannot determine which leaf is the real one, because the verification function provides no distinguishing information. This work is licensed under CC BY-SA 4.0. Commercial licensing (without ShareAlike) available on request: elissa_oui@outlook.com
Abstract. Quantum physics against intuition. Since Galileo, deeper understanding of physical reality often contradicts everyday’s intuition. This trend has become dramatic a century ago, rendering modern physics abstruse to the laymen. The scientist can exert his intuition and his imagination within an elaborate mathematical language, but it is impossible to translate his ideas faithfully into ordinary language; this difficulty may be one of the causes of the present tarnish of the image of science. A first shock was brought in by relativity, which revolutionized our conceptions of space and time, but quantum physics presents even more counter-intuitive features. One has been led to represent physical quantities pertaining to a system, such as the position or the velocity of a particle, no longer by ordinary numbers but by “observables”, mathematical objects which belong to a non-commutative algebra. Namely, the product of two such observables is not a unique new observable but may depend on their order: the products AB and BA may differ.The values that a physical quantity can take constitute a set of ordinary numbers, the eigenvalues a( n) of the observable A. This set may be discrete as a consequence of the algebra. The discreteness of the eigenvalues of the energy of an atom explains the spectrum of its radiation. Any component of the intrinsic angular momentum of an electron can take only two opposite values, baffling our geometric intuition.If two observables commute (i.e., AB = BA), they are compatible: both may take well-defined values chosen among the eigenvalues. If they do not commute (i.e., AB ≠ BA), which occurs for the position and velocity of a particle, for the electric and magnetic field, or for the components of an angular momentum, they are incompatible: their values cannot be measured nor even specified simultaneously. Each of them presents statistical fluctuations which must be larger than some lower bound (Heisenberg’s inequality). The state of a system, prepared under some definite conditions, should be identified as the set of expectation values of all observables.Thus, quantum physics, our most fundamental description of nature, is a theory involving irreducible probabilities and unavoidable uncertainties. Its predictions do not refer to a single system, but to a statistical ensemble, and the observer cannot be completely disregarded. Moreover it may involve aspects which are apparently contradictory (Bohr’s complementarity). An electron, an atom or a molecule may behave in limiting cases either as a particle or as a wave; under intermediate conditions, it behaves as both, but each of the descriptions is blurred with probabilities. As a wave, it can interfere with itself. Likewise, an electromagnetic field has the double nature of a set of photons and of a wave. At the macroscopic scale, relative fluctuations are small, so that determinism emerges.Quantum probabilities differ from standard ones. In particular, quantum correlations involving four observables pair wise violate Bell’s inequalities, so that microscopic quantities are intrinsically indeterminate and depend on the observation process.The GHZ paradox, due to Greenberger, Horne and Zeilinger, exemplifies the most troublesome conceptual feature of quantum physics. Indeed, it baffles not only intuition, but also current logics. It deals with a physical system made of three correlated particles. Various observables, A1, A2, A3, B1, B2 and B3 ≡ B1 B2, which we do not specify here, can be measured on such a composite system. Each of them may take discrete values a1 , a2, a3, b1, b2 equal either to +1 or to –1. Since the three observables A1 B1, A2 B2 and A3 B3 are compatible, they can be simultaneously controlled. Consider then a statistical ensemble of systems, all prepared identically in such a way that A1 B1 = A2 B2 = A3 B3 = +1. If we measure A1 and B1, we shall find either a1 = b1 = +1 or a1 = b1 = –1, that is always a1 = b1; likewise for a2 = b2 = ±1 and a3 = b1 b2 = ±1. We are tempted to infer that a simultaneous determination of the values a1, a2 and a3 of A1, A2 and A3 (which are compatible) should verify a3 = a1 a2, that is, a1 a2 a3 = 1. However both theory and experiment provide in all cases a1 a2 a3 = –1. In fact the four statements a1 = b1, a2 = b2, a3 = b1 b2 and a1 a2 a3 = –1 which seem contradictory are separately “true”, in the sense that each one can be verified experimentally; but such experiments cannot be performed on a single system. We are not allowed to make a logical reasoning based on a simultaneous consideration of the values of B1 and A2 because these observables do not commute. No calculation, no experiment can simultaneously provide values for the numbers b1 and a2. Hence, we cannot regard as true together the statements a1 = b1 and a2 = b2, although they can be checked by separate experiments. Each one is true, but their union is meaningless.Thus, if theory does not allow us to imagine thought experiments in which several statements on a system might simultaneously be checked, we cannot draw conclusions by putting such statements together. We are led to regard the “truth” of a quantum statement as contextual. The values of physical quantities are not attached only to the system in itself, but also refer to the context in which their relations may be verified. Quantum mechanics does not deal with objects per se, but with what we know and what we can infer about them. It does not provide a direct image of the reality of the object since it involves its observation. Although it is a perfect tool for letting us make statistical predictions, and although it appears as our most basic theory owing to its precision and generality, it violates our daily intuition, our elementary mathematical intuition and our feelings about reality. Its probabilities and even its logics obey rather shocking new rules.
Abstract. Deniable authentication is a technique that allows one party to send messages to another while the latter can not prove to a third party the fact of communication. In this paper, we first formalize a natural notion of deniable security and naturally extend the basic authenticator theorem by Bellare et al. [2] to the setting of deniable authentication. Of independent interest, this extension is achieved by defining a deniable MT-authenticator via a game. This game is essentially borrowed from the notion of universal composition [8] although we do not assume any result or background about it. Then we construct two deniable MT-authenticators: uncontrollable random oracle based and the PKI based, both of which are just 3-round protocols. The second construction assumes the receiver owns a secret key. Such a setup assumption is very popular in the real world. (Without this assumption), all the previous protocols do not have a widely satisfiable performance when applied in the Internet-like environment. Finally, as our application, we obtain key exchange protocols that is deniably secure in the real world. 1
The authentication code (A-code) is the one of the most fundamental cryptographic protocols in information-theoretic cryptography, and it provides information-theoretic integrity or authenticity, i.e., preventing information from being altered or substituted by the adversary having unbounded computational powers. In addition, it has a wide range of applications such as multiparty compu-tations and quantum key distribution protocols. The traditional A-code theory states that a good A-code is characterized as an A-code which satises equality of a lower bound on size of secret-keys, i.e., an A-code satisfying |K | = ϵ−2, where |K | is cardinality of the set of secret-keys and ϵ is the success probability of attacks of the adversary. However, good A-codes imply that secret-keys must be uniformly distributed. Therefore, if a non-uniformly random key is given, we cannot realize a good A-code by using it as a secret-key. Then, a natural question about this is: what is a good A-code having non-uniformly random keys? And, how can we design such a good A-code having non-uniformly random keys? To answer the questions, in this paper, we perform analysis of A-codes having non-uniformly random keys, and show the principle that guides the design for such good A-codes.
For the tilted family Jw=w(a1+a2−b1−b2)+∑ijsijEijJ_w = w(a_1+a_2-b_1-b_2) + \sum_{ij} s_{ij}E_{ij}Jw​=w(a1​+a2​−b1​−b2​)+∑ij​sij​Eij​ containing the I3322I_{3322}I3322​ Bell functional at w=1w=1w=1, we map where and why the almost-quantum set (NPA level 1+AB1{+}AB1+AB) exceeds NPA level 2, using a subset-relaxation diagnostic: adjoin the twelve level-2 words to the 1+AB1{+}AB1+AB basis in subsets and measure each subset's share of the gap. The excess is sharply localized and structurally rigid. (i) At w=1w=1w=1, the four matched words A1A2,A2A1,B1B2,B2B1A_1A_2, A_2A_1, B_1B_2, B_2B_1A1​A2​,A2​A1​,B1​B2​,B2​B1​ on the marginal-anchored settings recover 92% of the gap, while either party's complete pair structure, all eight third-setting words, and every mismatched cross-party pairing recover exactly none; at the level of the certified separation witness T∗T^*T∗, infeasibility appears already under a single cross-party pair of anchored words, one per wing, while every single-party and every third-setting subset leaves T∗T^*T∗ feasible. (ii) The mechanism is algebraic: reversal-symmetrized ordering differences obey ⟨A1A2BjB3⟩−⟨A1A2B3Bj⟩=12⟨[A1,A2][Bj,B3]⟩\langle A_1A_2B_jB_3\rangle - \langle A_1A_2B_3B_j\rangle = \frac{1}{2}\langle[A_1,A_2][B_j,B_3]\rangle⟨A1​A2​Bj​B3​⟩−⟨A1​A2​B3​Bj​⟩=21​⟨[A1​,A2​][Bj​,B3​]⟩, an expectation of commutator products across the wings, and sharp sequential measurement reads only anticommutators, so the excess lives in a sector unreadable in principle on either wing alone. (iii) The gap requires the functional's marginal anchor to oppose and co-locate with the aligned correlator block: moving either, aligning their signs, or deleting the marginals annihilates the gap. (iv) In the anchor weight the gap opens only on a finite window, w∈(0.90,0.95)w \in (0.90, 0.95)w∈(0.90,0.95) to (2.25,2.50)(2.25, 2.50)(2.25,2.50), with a two-lobed interior peaking near w=2w=2w=2 at 4.07×10−34.07\times10^{-3}4.07×10−3 -- 7.7 times the separation of standard I3322I_{3322}I3322​, which sits just inside the lower edge. Experiments probing the almost-quantum boundary should therefore run the tilted functional near w=2w=2w=2, not the textbook one. The headline values are certified in exact rational arithmetic: the two-word infeasibility of T∗T^*T∗, the matched-four value, the peak, and one closure; remaining grid values are floating-point with two solver families agreeing to five digits. Files in this record: the paper (PDF); exact rational proof objects for the four headline certificates (window_paper_certificates.json); a standalone verifier requiring only the Python 3 standard library (verify_window_certificates.py); analysis scripts (why_level2.py, anchor_tracking.py); and certificate generators (certify_window.py, refreeze_window.py). See README_window.txt. Companion record with the certified separation and its certificates: doi:10.5281/zenodo.21534675.
FINDING: Tsirelson's bound is the algebraic maximum quantum correlation 222\sqrt{2}22​ for the CHSH inequality, proven via operator norm constraints on anticommuting observables. | MATH: CHSH inequality classical bound = 2; quantum maximum = 22≈2.8282\sqrt{2} \approx 2.82822​≈2.828; Tsirelson's bound emerges from ∥A1B1+A1B2+A2B1−A2B2∥≤22\|A_1B_1 + A_1B_2 + A_2B_1 - A_2B_2\| \leq 2\sqrt{2}∥A1​B1​+A1​B2​+A2​B1​−A2​B2​∥≤22​ for self-adjoint operators Ai,BjA_i, B_jAi​,Bj​ with ∥Ai∥,∥Bj∥≤1\|A_i\|, \|B_j\| \leq 1∥Ai​∥,∥Bj​∥≤1 and [Ai,Bj]=0[A_i, B_j] = 0[Ai​,Bj​]=0. The proof uses the algebraic identity (A1+A2)B1+(A1−A2)B2(A_1 + A_2)B_1 + (A_1 - A_2)B_2(A1​+A2​)B1​+(A1​−A2​)B2​ and the C*-algebra norm inequality ∥X+Y∥2+∥X−Y∥2≤2(∥X∥2+∥Y∥2)\|X + Y\|^2 + \|X - Y\|^2 \leq 2(\|X\|^2 + \|Y\|^2)∥X+Y∥2+∥X−Y∥2≤2(∥X∥2+∥Y∥2). | CONNECTION: 222\sqrt{2}22​ is not a golden ratio constant, but the ratio 22/2=2≈1.4142\sqrt{2} / 2 = \sqrt{2} \approx 1.41422​/2=2​≈1.414 appears in crystallographic root systems (e.g., BnB_nBn​ lattice spacing) and in the diagonal of a unit square. The bound's algebraic structure involves anticommutation relations reminiscent of Clifford algebras, which underlie spinor representations and certain Author: Andrew Stewart Caldin, Independent Researcher, UK. Part of the E8 Intelligence Research series. Platform: e8intelligence.com