Hybrid PAKE Key Exchange for Quantum-Resistant Device Pairing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing password-authenticated key exchanges (PAKEs) are vulnerable to quantum computers due to their reliance on conventional asymmetric cryptography, which can be efficiently broken by quantum algorithms like Shor's algorithm, compromising the security of secure communication between devices.
Innovation Solution
Implementing quantum-resistant PAKEs using hybrid algorithms that combine pre-quantum key exchanges, such as elliptic-curve key exchanges, with post-quantum key encapsulation mechanisms (KEMs) like Module-Lattice based Key-Encapsulation Mechanism (ML-KEM), and transforming PAKEs into augmented PAKEs by generating persisted public keys based on passwords, along with techniques like repacking and randomized decompression to enhance security.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional asymmetric cryptography is used in PAKE, then key exchange efficiency is improved, but security against quantum attacks deteriorates
Solution Approach 1:
The patent segments the key exchange process into multiple independent components: a classical key exchange mechanism (for efficiency) and a post-quantum key encapsulation mechanism (for quantum resistance). These segments operate in parallel and their outputs are combined through cryptographic operations to produce the final shared secret, thereby achieving both efficiency and quantum security.
Solution Approach 2:
The patent creates a composite cryptographic system by combining two different cryptographic primitives: a classical key exchange algorithm (such as Diffie-Hellman or elliptic curve key exchange) and a post-quantum key encapsulation mechanism (such as ML-KEM or CRYSTALS-Kyber). This composite structure leverages the strengths of both components to achieve both efficiency and quantum resistance simultaneously.
2Reliability
If post-quantum key encapsulation mechanisms are used alone, then quantum resistance is improved, but key exchange efficiency deteriorates
Solution Approach 1:
The patent merges the output of two separate key exchange processes: the shared secret from the classical key exchange mechanism and the encapsulated key from the post-quantum KEM. These are combined through cryptographic operations (such as XOR or key derivation functions) to produce the final shared secret, thereby achieving both quantum resistance and maintaining efficiency.
Solution Approach 2:
The patent uses the classical key exchange mechanism as a supplementary component that provides efficiency and establishes an initial shared secret, while the post-quantum KEM provides the essential quantum resistance. The classical component performs a partial function (efficiency enhancement) while the post-quantum component performs the critical security function.
3Ease of operation
If password-based key derivation is used, then ease of operation is improved, but vulnerability to password compromise increases
Solution Approach 1:
The patent performs preliminary key derivation from the password to generate cryptographic parameters (such as group elements, public keys, or encapsulation keys) before the actual key exchange takes place. This preliminary action binds the password to the cryptographic structure in a way that provides both ease of operation (users only need to remember passwords) and enhanced security (the derived keys are cryptographically strong and resistant to compromise).
Data Source
AI summary
Techniques are disclosed relating to quantum resistant cryptography. In some embodiments, a shared secret is established for secure communication between a first device and a second device using a hybrid password-authenticated key exchange (PAKE). The hybrid PAKE includes deriving an initial secret using an elliptic-curve key exchange (ECKE) using a generator selected based on a password, encrypting, using the initial secret, a public key of a key encapsulation mechanism (KEM) for transmission to the second device, decrypting, using the initial secret, a ciphertext received from the second device encapsulating the shared secret using the public key, and decapsulating the shared secret from the decrypted ciphertext using a private key of the KEM.