Secure Spreadsheet Add-in for Private Multiparty Computation

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Solution Overview

Problem

Current spreadsheet technologies lack secure multiparty computation capabilities, leading to potential data loss and theft during collaborative calculations, as they require free data sharing, compromising privacy and ownership.

Innovation Solution

A user-programmable secure spreadsheet system that employs a parser module to generate secure programs using cryptographic protocols, allowing encrypted calculations without revealing user data, with the option to outsource computations to cloud systems for speed and security.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If users share data freely for collaborative calculations, then collaboration capability is improved, but data privacy and security deteriorate

Engineering Contradiction:
Improvecollaboration capabilityVSAvoiddata privacy
Core Design Contradiction:
Adaptability or versatilityVSLoss of information

Solution Approach 1:

The patent introduces a trusted third-party server as an intermediary that holds encryption keys and facilitates secure collaborative calculations. This mediator enables multiple users to perform joint computations on sensitive data without directly sharing the data or keys with each other, thus maintaining data privacy while achieving collaboration capability.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent segments the encryption keys among multiple users and the trusted server, with each party holding only a portion of the key. This segmentation ensures that no single user can access another user's data independently, as all key segments are required for decryption, thereby protecting data privacy while enabling collaborative access.

Inventive Principle:
Principle #1Segmentation

2Reliability

If secure computation protocols are implemented, then data security is improved, but computation speed deteriorates

Engineering Contradiction:
Improvedata securityVSAvoidcomputation speed
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The patent performs preliminary key distribution and encryption setup before the actual collaborative computations. By establishing the security infrastructure in advance, the system reduces the computational overhead during the actual calculation phase, thereby improving computation speed while maintaining data security.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent uses encrypted copies of data that can be processed without decrypting the original sensitive information. Users work with ciphertext versions of the data, performing calculations on the encrypted copies, which maintains security while enabling efficient computation without the need for repeated decryption operations.

Inventive Principle:
Principle #26Copying

3Reliability

If complex cryptographic protocols are used, then security level is improved, but system complexity deteriorates

Engineering Contradiction:
Improvesecurity levelVSAvoidsystem complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The trusted server acts as a mediator that handles the complex cryptographic operations, key management, and protocol coordination. This centralizes the complexity in a managed component rather than distributing it across all users, making the overall system easier to implement and maintain while achieving high security levels.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent designs a universal secure computation framework that can handle multiple types of collaborative calculations and security requirements through a single integrated system. This multi-functional approach reduces system complexity by providing a unified solution rather than requiring separate implementations for different computation scenarios.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Data Source

PatentEP3218800B1Secure multiparty computation on spreadsheets
Publication Date: 2023.06.07 CALCTOPIA LTD
  • EP3218800B1 patent drawingFigure 1~2
  • EP3218800B1 patent drawingFigure 3~4
  • EP3218800B1 patent drawingFigure 5~6

AI summary

Systems, computer-readable media and methods for enabling secure computation on spreadsheet software. A secure spreadsheet is implemented as an add-in to an existing spreadsheet program, or as a new spreadsheet program/web application, to allow secure computations on private input data (and also optionally with private functions) without the parties learning anything about them, via the familiar spreadsheet interface and its formula language. Automatic conversion of previous spreadsheet data and formulas is provided whenever possible, or assisted via a helper. The secure computation can be executed between the computers of the involved parties, or outsourced to a third-party -cloud computing system (FIG. 4)-: the secure cryptographic calculation module automatically optimizes for the best performing technique of secure computation (for example, homomorphic encryption, garbled circuits, oblivious transfers, secret sharing, oblivious random access machines and/or a combination of the previous crypto-primitives).