Quantum-safe Data Storage for App Developers with Open-Source Shamir Secret Sharing for Capacitor

How to build quantum-resistant apps with the Shamir Secret Sharing plugin for Capacitor?

The future of computing is knocking at our door. Quantum computers promise to revolutionize industries, solve impossible problems, and, unfortunately, break most of the encryption that protects our digital lives today.

This is where the Shamir Secret Sharing plugin for Capacitor plugin becomes your secret weapon for building truly resilient and secure apps.

What is Capacitor by Ionic?

Capacitor is an open-source, cross-platform native runtime that lets developers build iOS, Android, and web apps from a single modern JavaScript/TypeScript codebase. Created by the team behind Ionic, it provides a consistent API layer that bridges web technologies (like React, Vue, Angular, or vanilla JS) with native device capabilities such as secure storage, biometrics, filesystems, and more. Through its plugin system, Capacitor allows both first-party and community plugins—like Shamir Secret Sharing plugin for Capacitor—to expose powerful native functionality in a way that feels natural to web developers, enabling high-performance, production-grade apps without sacrificing the speed and flexibility of a web-based stack.

What are the challenges of Self-Custody?

We're witnessing a fundamental shift in how people think about their digital assets and personal data. From crypto wallets to personal health records, users increasingly want control over their own information. They don't want to trust centralized services with their most sensitive data.

But self-custody creates a terrifying problem: what happens when someone loses their phone, forgets their password, or worse—their device gets stolen? Traditional backup solutions force users to trust third parties or create single points of failure.

The Shamir Secret Sharing plugin for Capacitor plugin solves this elegantly by eliminating the need for any single point of trust or failure.

What is the mathematics behind Shamir's Secret Sharing?

Shamir's Secret Sharing reads like something from a cryptography fairy tale. Invented by Adi Shamir (the "S" in RSA encryption), this algorithm takes any secret and mathematically divides it into pieces called shards.

Here's where it gets beautiful: you can lose some shards and still recover your secret perfectly. Need 3 shards to reconstruct your data? Generate 5 shards and distribute them to trusted friends or devices. Even if 2 shards disappear forever, you can still recover everything.

But the real magic happens in what cryptographers call "information-theoretic security." Each individual share reveals absolutely nothing about your secret. Not a single bit of information leaks, no matter how powerful the computer trying to crack it.

This isn't just computationally difficult to break—its mathematically impossible. Even with unlimited processing power, an attacker with insufficient shards learns nothing. The mathematics guarantee this, not the limitations of current technology.

How do you Future-proof against quantum threats?

Most encryption today relies on mathematical problems that are hard for classical computers to solve. Factoring large prime numbers takes classical computers thousands of years. Quantum computers could solve these same problems in hours.

Shamir's Secret Sharing takes a completely different approach. Its security doesn't depend on computational difficulty—it depends on mathematical impossibility. Think of it like trying to solve an equation with fewer values than unknowns. There are infinite equally valid solutions, making it impossible to determine which one is correct.

This information-theoretic approach means quantum computers offer no advantage to attackers. The underlying mathematics remain just as secure whether facing classical computers, quantum computers, or hypothetical super-quantum computers that might emerge decades from now.

Your applications built with the Shamir Secret Sharing plugin for Capacitor today will remain secure through whatever computing revolution comes next.

How can you Fault-proof your apps through distribution

Traditional security models create single points of failure. Lose your password manager database? Everything's gone. Company servers get compromised? Your data's exposed. Phone gets stolen? Access to your accounts vanishes.

Shamir's Secret Sharing flips this model entirely. Instead of protecting one critical thing perfectly, you distribute security across multiple independent channels. Each share can live in a different place:

• One share encrypted by your phone's secure enclave
• Another with a trusted friend or family member
• A third is stored in a safety deposit box
• Additional shards distributed to other devices or locations

The threshold system means you're protected against multiple simultaneous failures. Device breaks? Friend moves abroad? Safety deposit box becomes inaccessible? Your system keeps working because no single failure can compromise your security.

This distributed approach creates applications that become more resilient as they scale, not more vulnerable.

What are Common Use Cases for the Shamir's Secret Sharing Capacitor Plug-in?

The Shamir Secret Sharing plugin for Capacitor plugin provides the foundation, but imagination determines the possibilities. Consider these emerging use cases:

Family digital inheritance becomes possible when crypto seeds or important documents are shared across trusted family members. Parents can ensure their digital assets transfer smoothly without exposing sensitive information during their lifetime. That's what the Vault12 Guard app does by using Shamir Secret Sharing plugin for Capacitor.

Collaborative authentication allows teams to protect shared resources without any single administrator having complete control. Critical business systems require multiple people to authorize changes, preventing both external attacks and insider threats.

Progressive disclosure enables applications that reveal information only when specific conditions are met. Legal documents that unlock automatically when multiple parties agree, or time-locked messages that require distributed consent to access early.

Redundant backup systems can store encrypted application state across multiple cloud providers, user devices, and physical locations. Users never lose access to their data, but no single provider ever has complete information.

The plugin's cross-platform nature—supporting iOS, Android, and web—means these experiences work seamlessly across all user devices and contexts.

How has the Shamir's Secret Sharing Capacitor Plug-in been tried and tested in commercial apps?

The convergence of quantum computing, increased privacy awareness, and demand for user-controlled applications creates unprecedented opportunities for developers who think ahead.

Applications built with traditional security models will face obsolescence as quantum computers emerge. Centralized platforms will struggle as users demand true ownership of their data. Single points of failure will become unacceptable as digital stakes continue rising.

But developers using Shamir Secret Sharing plugin for Capacitor can build applications that thrive in this new landscape. Your users get genuine self-custody without sacrificing usability. Your architecture becomes more resilient as it scales. Your security improves as computing power increases rather than becoming more vulnerable.

The plugin abstracts away the complex mathematics and cross-platform implementation details. You get enterprise-grade Shamir's Secret Sharing through simple TypeScript interfaces, letting you focus on creating innovative user experiences rather than cryptographic implementation.

How can you start using the Shamir's Secret Sharing Capacitor Plug-in?

Quantum computers won't wait for our applications to catch up. User expectations for data ownership and privacy continue accelerating. The developers who start building quantum-resistant, fault-proof applications today will define the next generation of digital experiences.

The Shamir Secret Sharing plugin for Capacitor plugin gives you the tools. The mathematical foundations are unshakeable. The production validation is complete. The cross-platform compatibility ensures a broad reach.

What remains is the most exciting part: imagining and building the resilient, user-empowering applications that will define computing's next chapter. The future belongs to developers who understand that true security comes not from building higher walls, but from removing single points of failure entirely.

Your users are ready for applications they can truly trust. The technology is ready to support your vision. The question is: what will you build?

Using the Shamir Secret Sharing plugin for Capacitor - Github: https://github.com/vault12/capacitor-shamir

What is Shamir's Secret Sharing?

Shamir's Secret Sharing is a cryptographic algorithm that divides a secret into multiple parts (shards), where a minimum threshold of shards is required to reconstruct the original secret. This ensures that:

• No single shard reveals any information about the secret
• Any threshold number of shards can reconstruct the secret
• Security through distribution - store shards separately for maximum security

What are the Security Concepts behind Shamir's Secret Sharing?

Shamir's Secret Sharing provides information-theoretic security, which means the algorithm is mathematically proven to be unbreakable regardless of computational power. Key security advantages:

• Quantum Resistance: Security relies on mathematical impossibility rather than computational complexity, remaining secure against quantum computers
• No Key Management: There is no single master key to rotate or protect; instead, security hinges on distributing and safeguarding the individual shards
• Mathematical Foundation: Based on polynomial interpolation over finite fields, where reconstructing the secret without sufficient shards is mathematically impossible, not just computationally difficult

What are the features of Shamir's Secret Sharing Capacitor Plug-in?

• Secure Secret Splitting: Split sensitive data into encrypted shards using Shamir's Secret Sharing
• Cross-Platform: Native support for iOS, Android, and Web
• Flexible Storage: Memory-based and filesystem-based operations
• Progress Tracking: Real-time progress callbacks for all operations
• Performance Optimized: Efficient handling of large files and data
• Recovery Options: Restore complete secrets or individual shards

What are examples of Real-World Usage?

This plugin has already been battle-tested in production for a decade on almost a million iOS and Android devices, as a core component of Vault12 Guard, a mobile app that provides decentralized backup, and inheritance for crypto wallets and other sensitive data.

More information is at Github: https://github.com/vault12/capacitor-shamir