Overview
ISO/IEC 11770-4:2017/Amd 1:2019 is an international standard amendment focused on security techniques in information technology, specifically addressing key management mechanisms based on weak secrets. This amendment introduces the Unbalanced Password-Authenticated Key Agreement with Identity-Based Cryptosystems (UPAKA-IBC). It advances authentication protocols by combining password-based weak secrets with strong, identity-related cryptographic keys, enhancing security for applications with asymmetric trust requirements, such as client-server models.
UPAKA-IBC integrates password authentication with identity-based cryptography (IBC), where public keys are derived from unique identity strings (e.g., email or IP address) and private keys are computed securely by a trusted private key generator. This unbalanced approach allows entities like clients and servers to establish shared secret keys safely, minimizing risks like server impersonation attacks while maintaining usability with human-memorable passwords.
Key Topics
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Unbalanced Key Agreement
This mechanism involves two entities with differing secret strengths: one holds a weak secret (typically password-based), and the other holds a strong secret coupled with verification data derived from the weak secret.
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Identity-Based Cryptosystems (IBC)
A cryptographic system where public keys correspond to unique, easily recognizable identifiers, streamlining key management. The private keys are generated by a trusted authority using a master-secret key, domain parameters, and the entity’s identity.
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UPAKA-IBC Components
- Initialization with domain parameters and password-based secrets
- Key token generation and exchange involving encrypted and password-entangled tokens
- Validation of key tokens to prevent unauthorized access
- Derivation of shared secret keys leveraging both weak and strong secrets
- Optional key confirmation to verify successful key agreement
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Security Considerations
The standard mandates countermeasures against online guessing attacks by incorporating mechanisms such as failed login counters and the tracking of authentication events.
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Two Mechanism Types
- UKAM-PiE: Unbalanced Key Agreement with Password and Identity-based Encryption
- UKAM-PiS: Unbalanced Key Agreement with Password and Identity-based Signature
Applications
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Client-Server Authentication
UPAKA-IBC is highly suitable for models where clients use short, memorable passwords while servers maintain long, strong cryptographic keys. This balances convenience with high security essential for modern online services.
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Secure Key Management in Weak Secret Environments
This standard is ideal for environments where user credentials are inherently weak (passwords), protecting secret key exchanges against attacks that exploit these weaknesses.
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Identity-Based Network Security
Organizations can leverage identity-based key management to streamline public key infrastructure (PKI) complexity, reducing overhead in managing certificates while enhancing trust assurances.
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Protection Against Server Impersonation Attacks
By combining password authentication with identity-based cryptography, UPAKA-IBC offers robust defense mechanisms against attackers masquerading as legitimate servers.
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Systems Requiring Efficient Key Derivation with Passwords
Systems needing frequent password-based authentication while ensuring strong cryptographic key exchanges can implement UPAKA-IBC to improve both security and operational efficiency.
Related Standards
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ISO/IEC 11770-1 to -3: These parts provide foundational guidance on key management fundamentals, mechanisms based on symmetric and asymmetric techniques, complementing the mechanisms based on weak secrets discussed here.
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ISO/IEC 18033-5: Details identity-based encryption schemes, defining algorithms and parameters essential for implementing the IBC mechanisms integrated into UPAKA-IBC.
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ISO/IEC 27001 & 27002: Provide overarching information security management frameworks related to establishing, implementing, and maintaining secure key management practices inclusive of those outlined in ISO/IEC 11770-4.
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ISO/IEC Directives, Part 1 & 2: Govern the procedural and editorial rules under which this and other ISO/IEC standards are developed and maintained.
Summary
ISO/IEC 11770-4:2017/Amd 1:2019 enhances existing key management standards by introducing the UPAKA-IBC mechanism, enabling secure password-authenticated key agreements using identity-based cryptosystems. This approach is particularly effective in asymmetric trust environments such as client-server architectures, reinforcing server authentication and protecting against common cyber threats like impersonation and guessing attacks. Implementing this standard supports organizations in achieving robust, scalable, and user-friendly security protocols in password-based authentication contexts.
Keywords: ISO/IEC 11770-4, key management, security techniques, weak secrets, password-authenticated key agreement, identity-based cryptosystems, UPAKA-IBC, unbalanced key agreement, UKAM-PiE, UKAM-PiS, password security, client-server authentication, cryptographic key exchange.
Open preview (PDF)Information technology — Security techniques — Key management — Part 4: Mechanisms based on weak secrets — Amendment 1: Unbalanced Password-Authenticated Key Agreement with Identity-Based Cryptosystems (UPAKA-IBC)