Information-theoretically secure signatures speed up permissioned blockchain consensus
SILMARILS-MV: Information-Theoretically Secure Multi-Verifier Signatures with Dealer-Free Key Issuance and Linear Aggregation for Permissioned Blockchains
Cryptography and SecurityDistributed, Parallel, and Cluster ComputingInformation Theory
Summary
Permissioned blockchains need secure ways to verify transactions that are safe even against future quantum computers. Existing methods either rely on trusted authorities or require costly communication and key use restrictions. The authors present SILMARILS-MV, a new cryptographic scheme that ensures signatures remain secure against unlimited attackers without needing a trusted dealer, special quantum channels, or frequent key changes. Their design supports fast verification and aggregation, reduces communication overhead, and scales efficiently to hundreds or thousands of participants.
What this means in practice
- •For blockchain infrastructure teams: Implement low-overhead, quantum-resistant consensus signatures to speed up transaction finality and reduce network load in permissioned blockchains.
- •For enterprise security engineers: Deploy dealer-free, secure key issuance for distributed signing in multi-organization blockchain networks to enhance decentralization and robustness.
Authors
Khadijeh Bagheri, Hassan Khodaiemehr, Chen Feng
Abstract
Permissioned blockchains authenticate transactions, votes and quorum certificates with computationally secure signatures, and post-quantum replacements inflate consensus traffic by orders of magnitude. Information-theoretic alternatives have required a trusted authority, quantum channels, per-signature interaction, or single-use keys with bounded transfer. We present SILMARILS-MV, a multi-verifier unconditionally secure signature in which a signature is the vector $α= A\,e(m)$ and each verifier holds a secret functional $c_i = Γ^T λ(x_i)$ derived from virtual anchors $Γ$ that nobody learns. Against unbounded adversaries corrupting up to $ω$ verifiers and any signers, and observing every decision, an honest verifier accepts a forged or invalid signature with probability at most $Q/q + 1/(q-1)$, a bound that is tight in its leading term. The scheme is strongly unforgeable, non-repudiable, transferable across unboundedly many hops, and linearly aggregatable. Keys are issued by the validators through perfectly secure MPC for $t < n/3$, without broadcast. To scale, we let the committee itself sign: in threshold notarization, finality certificates have constant size $32(ω+1)$ bytes and per-validator issuance cost no longer depends on $n$. Arbiter-verified keys give clients 32-byte signatures, robust redistribution supports membership changes and share refresh, and verifiers can be enrolled retroactively. A certificate verifies in 2.4 microseconds. In an analytic normal-case model at 1000 validators, threshold notarization needs 71 KiB of authentication traffic per validator per block, 22x less than ML-DSA-44 for admitted verifiers. In a Rust HotStuff prototype with 100 validators, SILMARILS-MV commits 2.8x more transactions per second than ML-DSA-44 with 67x less cryptographic CPU, and Monte-Carlo attacks match the bounds.