Asymptotically Ideal Hierarchical Secret Sharing Based on CRT for Integer Ring
Pith reviewed 2026-05-15 00:47 UTC · model grok-4.3
The pith
Two CRT-based schemes for hierarchical secret sharing become asymptotically ideal in information rate.
A machine-rendered reading of the paper's core claim, the machinery that carries it, and where it could break.
Core claim
The authors construct disjunctive and conjunctive hierarchical secret sharing schemes via the CRT for the integer ring and one-way functions; both schemes are asymptotically ideal, with information rate approaching 1, and are proven secure under standard assumptions on the one-way functions.
What carries the argument
Chinese Remainder Theorem decomposition over integer moduli chosen to encode the hierarchical access structure, combined with one-way functions that mask the shares so that the total share size stays close to the secret size.
If this is right
- Authorized sets at or above the required level reconstruct the secret exactly.
- Any set that fails the hierarchical condition obtains zero information about the secret.
- Share sizes increase only by a multiplicative factor that can be made arbitrarily close to 1.
- The schemes inherit the flexible share-size property of CRT methods while removing the previous rate limitation.
Where Pith is reading between the lines
- In large-scale distributed storage the storage cost per secret would approach the information-theoretic minimum even when participants have graded privileges.
- An efficient, explicit algorithm for selecting the CRT moduli would turn the asymptotic result into a practical construction for concrete sizes.
- The same masking technique with one-way functions might be reusable for realizing other monotone access structures beyond the hierarchical case.
Load-bearing premise
There exist sequences of CRT moduli that simultaneously realize the required hierarchical access structure and drive the information rate arbitrarily close to one.
What would settle it
A concrete counterexample would be any hierarchical access structure for which every choice of moduli forces the sum of share lengths to remain at least twice the secret length for arbitrarily large participant counts, or an efficient algorithm that recovers the secret from the shares held by any unauthorized set.
read the original abstract
In Shamir's secret sharing scheme, all participants possess equal privileges. However, in many practical scenarios, it is often necessary to assign different levels of authority to different participants. To address this requirement, Hierarchical Secret Sharing (HSS) schemes were developed, which partitioned all participants into multiple subsets and assigned a distinct privilege level to each. Existing Chinese Remainder Theorem (CRT)-based HSS schemes benefit from flexible share sizes, but either exhibit security flaws or have an information rate less than $\frac{1}{2}$. In this work, we propose a disjunctive HSS scheme and a conjunctive HSS scheme by using the CRT for integer ring and one-way functions. Both schemes are asymptotically ideal and are proven to be secure.
Editorial analysis
A structured set of objections, weighed in public.
Referee Report
Summary. The manuscript proposes a disjunctive hierarchical secret sharing (HSS) scheme and a conjunctive HSS scheme constructed via the Chinese Remainder Theorem over the integer ring combined with one-way functions. It asserts that both schemes are asymptotically ideal (information rate approaching 1) and supplies security proofs, improving on prior CRT-based HSS schemes that either had security flaws or information rates below 1/2.
Significance. If the constructions and proofs are valid, the work would provide a meaningful advance in HSS by delivering asymptotically ideal rates with the flexibility of CRT-based share sizes, while using one-way functions to enforce hierarchy. This could be useful for applications needing graded access privileges, provided the modulus selection is efficient and the security reductions are tight.
major comments (2)
- [Abstract] Abstract: the central claims of asymptotic ideality and security are asserted without any derivation steps, explicit modulus conditions, or reduction details; this is load-bearing because the abstract supplies no concrete algorithm or existence argument for the required CRT moduli.
- [Construction] Construction section: no explicit (poly-time) algorithm is given for producing a modulus tuple M_1 < … < M_n that simultaneously enforces the stated disjunctive or conjunctive hierarchy via CRT reconstruction and guarantees max |share_i| / |secret| → 1; without a density proof for suitable primes, the rate claim risks collapse if |M_i| must grow linearly with the number of participants.
minor comments (2)
- [Preliminaries] Notation for the hierarchical access structures should be introduced with a small example table showing how the disjunctive versus conjunctive conditions translate into the CRT conditions.
- [Security Analysis] Ensure that all references to one-way functions include the precise hardness assumption used in the security reduction.
Simulated Author's Rebuttal
We thank the referee for the careful reading and constructive comments. We address each major point below and will revise the manuscript to incorporate clarifications and an explicit algorithm.
read point-by-point responses
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Referee: [Abstract] Abstract: the central claims of asymptotic ideality and security are asserted without any derivation steps, explicit modulus conditions, or reduction details; this is load-bearing because the abstract supplies no concrete algorithm or existence argument for the required CRT moduli.
Authors: We agree the abstract is concise and will revise it to include a brief statement of the key modulus conditions (strictly increasing primes M_i of bit length approximately equal to the secret) and note that security follows from the one-wayness of the functions used to enforce hierarchy levels. Full derivation steps and reductions remain in the body, but the abstract will now reference the existence argument based on prime density in short intervals. revision: yes
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Referee: [Construction] Construction section: no explicit (poly-time) algorithm is given for producing a modulus tuple M_1 < … < M_n that simultaneously enforces the stated disjunctive or conjunctive hierarchy via CRT reconstruction and guarantees max |share_i| / |secret| → 1; without a density proof for suitable primes, the rate claim risks collapse if |M_i| must grow linearly with the number of participants.
Authors: The one-way functions in our construction enforce the hierarchy, permitting moduli to be chosen without exponential growth. We will add an explicit probabilistic polynomial-time algorithm: given security parameter l (secret bit length) and n, iteratively select the next prime in [2^l, 2^{l+1}] satisfying the (loose) CRT conditions for the hierarchy. Prime gaps of size O(l^2) ensure efficiency. By the prime number theorem, sufficiently many such primes exist for polynomial n in l, and |M_i| = l + o(l), so the information rate approaches 1 as l → ∞. A short density argument and reference will be included. revision: yes
Circularity Check
No circularity: construction and proofs rely on external CRT and OWF properties
full rationale
The paper defines two HSS schemes via explicit CRT-based share generation over integer rings combined with one-way functions to enforce hierarchy. Security reductions are stated to rest on the one-wayness of the hiding function and on the standard uniqueness of CRT solutions for the chosen moduli. Asymptotic ideality is obtained by letting the secret size grow while keeping the relative size of the largest modulus bounded; this bound is asserted to be achievable by standard prime-density arguments rather than by any quantity defined in terms of the final rate. No equation equates a derived quantity to a fitted parameter or to a self-cited uniqueness theorem; the derivation chain is therefore independent of its own outputs.
Axiom & Free-Parameter Ledger
axioms (2)
- domain assumption Secure one-way functions exist
- domain assumption Suitable CRT moduli can be chosen to realize the hierarchical access structure while preserving asymptotic ideality
Reference graph
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discussion (0)
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