# information-theoretic security

> security of a cryptosystem which derives purely from information theory

**Wikidata**: [Q3510462](https://www.wikidata.org/wiki/Q3510462)  
**Wikipedia**: [English](https://en.wikipedia.org/wiki/Information-theoretic_security)  
**Source**: https://4ort.xyz/entity/information-theoretic-security

## Summary
Information-theoretic security refers to the security of a cryptosystem that derives its protection purely from information theory principles, meaning it guarantees security even against an attacker with unlimited computational power.

## Key Facts
- Security of a cryptosystem which derives purely from information theory
- Part of the broader field of cryptography
- Also known as "inconditional security" (from the French alias)
- Belongs to the category of information-theoretically secure algorithms
- Related to Shamir's Secret Sharing algorithm in cryptography
- Has Wikipedia presence in multiple languages including English, French, German, and others
- Has 11 sitelink references on Wikipedia

## FAQs
### Q: What is the main characteristic of information-theoretic security?
A: It provides security based solely on information theory principles, guaranteeing protection even against an attacker with unlimited computational resources.

### Q: How is information-theoretic security different from other security models?
A: It differs from computational security models that rely on assumptions about computational difficulty, instead guaranteeing security based on fundamental information theory principles.

### Q: What is the relationship between information-theoretic security and cryptography?
A: Information-theoretic security is a subset of cryptography, specifically referring to cryptographic systems whose security is guaranteed by information theory rather than computational complexity.

## Why It Matters
Information-theoretic security represents a fundamental approach to cryptographic security that provides absolute guarantees. Unlike computational security models that rely on assumptions about the difficulty of solving mathematical problems, information-theoretic security offers provable guarantees based on information theory principles. This approach is particularly important for applications where absolute security is required, such as in certain government communications or systems where computational power might increase over time. The concept ensures that no matter how much computational power an attacker possesses, they cannot break the system, providing a strong theoretical foundation for secure communication.

## Notable For
- Provides absolute security guarantees based on information theory principles
- Represents a fundamental approach to cryptographic security
- Guarantees protection even against unlimited computational power
- Is distinct from computational security models that rely on complexity assumptions
- Forms the theoretical basis for certain cryptographic algorithms and protocols
- Has been studied and developed as a core concept in modern cryptography

### Theoretical Foundations
Information-theoretic security is grounded in information theory principles, particularly the concept of entropy and information content. This approach ensures that the security of a cryptosystem is independent of computational power, making it particularly relevant for applications where absolute security is paramount. The concept has been formalized through various theoretical frameworks that establish the conditions under which a cryptosystem can be considered information-theoretically secure.

### Practical Applications
While many modern cryptographic systems rely on computational assumptions, information-theoretic security remains important for specific applications where absolute security is required. These include certain government communications, secure financial transactions, and systems where the security of the communication channel cannot be guaranteed. The theoretical guarantees provided by information-theoretic security offer a baseline for evaluating the security of cryptographic systems.

### Historical Development
The concept of information-theoretic security has evolved alongside the development of cryptography as a field. Early work in information theory established the theoretical foundations, while subsequent developments have refined the understanding of how information-theoretic principles can be applied to practical cryptographic systems. The approach has influenced the development of various cryptographic algorithms and protocols that aim to provide absolute security guarantees.

### Comparison with Other Security Models
Information-theoretic security differs fundamentally from computational security models that rely on assumptions about the difficulty of solving mathematical problems. While computational security may be broken if computational power increases sufficiently, information-theoretic security provides absolute guarantees regardless of computational capabilities. This distinction is crucial for understanding the different security guarantees offered by various cryptographic approaches.

## References

1. [OpenAlex](https://docs.openalex.org/download-snapshot/snapshot-data-format)