---
_id: '63403'
abstract:
- lang: eng
  text: "Stateful signatures like the NIST standardized signature schemes LMS and
    XMSS provide an efficient and mature realization of post-quantum secure signature
    schemes. They are recommended for long-term use cases like e.g. firmware signing.
    However, stateful signature schemes require to properly manage a so-called state.
    In stateful signature schemes like LMS and XMSS, signing keys consist of a set
    of keys of a one-time signature scheme and it has to be guaranteed that each one-time
    key is used only once. This is done by updating a state in each signature computation,
    basically recording which one-time keys have already been used. While this is
    straightforward in centralized systems, in distributed systems like secure enclaves
    consisting of e.g. multiple hardware security modules (HSMs) with limited communication
    keeping a distributed state that at any point in time is consistent among all
    parties involved presents a challenge. This challenge is not addressed by the
    current standardization processes. \r\nIn this paper we present a security model
    for the distributed key management of post-quantum secure stateful signatures
    like XMSS and LMS. We also present a simple, efficient, and easy to implement
    protocol proven secure in this security model, i.e. the protocol guarantees at
    any point in time a consistent state among the parties in a distributed system,
    like a distributed security enclave. The security model is defined in the universal
    composabilty (UC) framework by Ran Canetti by providing an ideal functionality
    for the distributed key management for stateful signatures. Hence our protocol
    remains secure even if arbitrarily composed with other instances of the same or
    other protocols, a necessity for the security of distributed key management protocols.
    Our main application are security enclaves consisting of HSMs, but the model and
    the protocol can easily be adapted to other scenarios of distributed key management
    of stateful signature schemes."
author:
- first_name: Johannes
  full_name: Blömer, Johannes
  id: '23'
  last_name: Blömer
- first_name: Henrik
  full_name: Bröcher, Henrik
  id: '41047'
  last_name: Bröcher
  orcid: 0009-0008-3938-5485
- first_name: Volker
  full_name: Krummel, Volker
  last_name: Krummel
- first_name: Laurens Alexander
  full_name: Porzenheim, Laurens Alexander
  id: '47434'
  last_name: Porzenheim
citation:
  ama: Blömer J, Bröcher H, Krummel V, Porzenheim LA. Secure Distributed State Management
    for Stateful Signatures with a Practical and Universally Composable Protocol.
  apa: Blömer, J., Bröcher, H., Krummel, V., &#38; Porzenheim, L. A. (n.d.). <i>Secure
    Distributed State Management for Stateful Signatures with a Practical and Universally
    Composable Protocol</i>.
  bibtex: '@article{Blömer_Bröcher_Krummel_Porzenheim, title={Secure Distributed State
    Management for Stateful Signatures with a Practical and Universally Composable
    Protocol}, author={Blömer, Johannes and Bröcher, Henrik and Krummel, Volker and
    Porzenheim, Laurens Alexander} }'
  chicago: Blömer, Johannes, Henrik Bröcher, Volker Krummel, and Laurens Alexander
    Porzenheim. “Secure Distributed State Management for Stateful Signatures with
    a Practical and Universally Composable Protocol,” n.d.
  ieee: J. Blömer, H. Bröcher, V. Krummel, and L. A. Porzenheim, “Secure Distributed
    State Management for Stateful Signatures with a Practical and Universally Composable
    Protocol.” .
  mla: Blömer, Johannes, et al. <i>Secure Distributed State Management for Stateful
    Signatures with a Practical and Universally Composable Protocol</i>.
  short: J. Blömer, H. Bröcher, V. Krummel, L.A. Porzenheim, (n.d.).
date_created: 2025-12-22T21:23:22Z
date_updated: 2025-12-23T11:30:38Z
department:
- _id: '34'
- _id: '64'
keyword:
- distributed state
- hash-based signature
- stateful hash-based signature
- universal composability
- secure enclave
language:
- iso: eng
main_file_link:
- open_access: '1'
  url: https://eprint.iacr.org/2025/2278.pdf
oa: '1'
page: '22'
project:
- _id: '191'
  name: 'PhoQuant: Photonische Quantencomputer -  Quantencomputing Testplattform'
publication_status: submitted
status: public
title: Secure Distributed State Management for Stateful Signatures with a Practical
  and Universally Composable Protocol
type: preprint
user_id: '41047'
year: '2025'
...