Overview
ISO/IEC 19592-1:2016 - Information technology - Security techniques - Secret sharing - Part 1: General - defines the general model, terminology and parameters for cryptographic secret sharing schemes. The standard specifies the parties (dealer, share-holder, receiver), the components of a scheme (message sharing and message reconstruction algorithms), and fundamental concepts such as message space, share space, share vector, number of shares, access structure and thresholds. It also describes required and optional properties (confidentiality, recoverability, homomorphicity, verifiability) and implementation considerations like erasing dealer copies after distribution.
Key Topics and Requirements
- Roles and processes
- Dealer: runs the message sharing algorithm and distributes shares.
- Share-holder: stores assigned shares.
- Receiver: collects shares and runs the reconstruction algorithm.
- Parameters every instantiation must define
- Message space and share space - the domains for secrets and shares.
- Number of shares (n) and any permitted range.
- Access structure - the minimal subsets of share-holders that can reconstruct the secret; may be threshold-based (k-of-n) or custom.
- Core properties
- Message confidentiality - unauthorized subsets learn nothing about the secret.
- Message recoverability - authorized subsets can reconstruct the secret.
- Optional properties include homomorphicity (support for operations on shares) and verifiability (detection of incorrect shares).
- Other considerations
- Complexity, information rate, and confidentiality guarantees are addressed to compare and evaluate schemes.
- Practical implementation notes such as secure storage of shares and potential erasure of dealer copies.
Applications
ISO/IEC 19592-1:2016 frames secret sharing for practical security use cases:
- Protecting cryptographic keys and confidential values in distributed storage.
- Enabling secure multi-party computation by distributing inputs across parties.
- Building resilient key management systems, threshold cryptography, and split-trust architectures.
- Use in blockchain custodial solutions, hardware security module (HSM) backup strategies, and secure cloud storage where no single party should hold a complete secret.
Who should use this standard
- Security architects and system designers implementing distributed key storage or threshold schemes.
- Cryptographers and protocol developers defining secret sharing instantiations.
- Auditors, compliance officers and product teams verifying interoperability and security properties.
- Standards bodies and implementers integrating secret sharing into distributed systems and secure multi-party computation.
Related Standards
- Part of the ISO/IEC 19592 series (see ISO website for other parts). Developed by ISO/IEC JTC 1/SC 27 (IT Security techniques) to ensure interoperability and consistent terminology across secret sharing implementations.
Keywords: ISO/IEC 19592-1:2016, secret sharing, secret sharing schemes, access structure, threshold secret sharing, message sharing algorithm, message reconstruction, cryptographic secret sharing, secure multi-party computation.