Tamper-Proof Token for Secure Oblivious Transfer

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Existing cryptographic methods for secure function evaluation (SFE) are computationally intensive due to the reliance on public key encryption techniques for oblivious transfer of secret keys, which may not provide security against malicious attackers.

Innovation Solution

A tamper-proof token generated by one party is used, which includes a strong pseudorandom function generator (SPRFG) to securely transfer one of two secret keys to the other party for calculations, ensuring the receiving party cannot learn the full private information and the sending party is not aware of which key was transferred, utilizing a resettable token to enhance security.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If public key encryption techniques are used for oblivious transfer of secret keys, then security is provided, but computational intensity increases significantly

Engineering Contradiction:

ImprovesecurityVSAvoidcomputational effort

Core Design Contradiction:

ReliabilityVSUse of energy by moving object

Solution Approach 1:

The patent introduces a tamper-proof token as an intermediary device that stores secret keys and provides them to the receiving party through a simplified transfer mechanism. This token-based intermediary eliminates the need for computationally intensive public key encryption operations while maintaining security, as the token physically contains the keys and can only be read by authorized parties.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent replaces the cryptographic mechanical system (public key encryption) with a physical token-based system. Instead of using complex encryption algorithms to transfer keys, the invention uses a physical token that mechanically stores and provides keys, substituting computational cryptography with physical security mechanisms.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Ease of operation

If traditional oblivious transfer methods are used, then key transfer is achieved, but the receiving party can potentially reset the token to compromise security

Engineering Contradiction:

Improvekey transfer capabilityVSAvoidsecurity against malicious attackers

Core Design Contradiction:

Ease of operationVSReliability

Solution Approach 1:

The patent applies preliminary anti-action by designing the tamper-proof token with inherent anti-reset capabilities built into its physical structure and operational mechanism. The token is designed from the outset to prevent any resetting or state change by the receiving party, counteracting potential malicious actions before they can occur.

Inventive Principle:

Principle #9Preliminary anti-action

Solution Approach 2:

The patent employs a disposable or single-use token model where the token is transferred from the sending party to the receiving party and cannot be reused or reset. This disposable approach ensures that even if the receiving party attempts to compromise the token, the security is maintained because the token cannot be reset to its original state.

Inventive Principle:

Principle #27Cheap short-living objects (Disposable)

3Productivity

If full private information is transferred to the receiving party, then calculations can be performed, but privacy protection is compromised

Engineering Contradiction:

Improvecalculation capabilityVSAvoidprivacy protection

Core Design Contradiction:

ProductivityVSLoss of information

Solution Approach 1:

The patent extracts only the necessary portion of private information (the secret key) from the full private information set and transfers it through the tamper-proof token. This extraction allows the receiving party to perform calculations using the key while the rest of the private information remains protected and unknown to the receiving party.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The patent applies local quality by providing the receiving party with access to specific local information (the secret key for calculations) while maintaining that the rest of the private information remains hidden. The token provides localized key access without exposing the broader private information landscape.

Inventive Principle:

Principle #3Local quality

Data Source

PatentUS8923519B2Method of efficient secure function evaluation using resettable tamper-resistant hardware tokens

Publication Date: 2014.12.30 WSOU INVESTMENTS LLC

AI summary

An embodiment of the present invention provides a computer implemented method for the transfer of private information of one user to another user—a primitive known as Oblivious Transfer. An output from a strong pseudorandom function generation (SPRFG) is calculated by a first user's computing module based on first and second parameters: the first parameter specifying one of two secret keys; the second parameter being a value selected within the domain of the SPRFG by the first user. The first user is prevented from reading or learning the stored two secret keys. The output is transmitted to a computer of a second user which generates first and second encrypted values that are each based on an inverse SPRFG calculation using the first and second secret keys, respectively, and corresponding private values of the second user. The encrypted values are sent to a first computer of the first user that calculates one of the private values using a mathematical computation based on the second parameter and the one of the first and second encrypted values that corresponds to the one of the first and second key used.