# Oblivious transfer

> type of cryptography protocol

**Wikidata**: [Q2915383](https://www.wikidata.org/wiki/Q2915383)  
**Wikipedia**: [English](https://en.wikipedia.org/wiki/Oblivious_transfer)  
**Source**: https://4ort.xyz/entity/oblivious-transfer

## Summary
Oblivious transfer is a type of cryptography protocol that allows a sender to transfer one of multiple pieces of information to a receiver without knowing which piece was received. It was invented by Michael O. Rabin in 1981 and serves as a fundamental building block for more complex cryptosystems.

## Key Facts
- Invented by Michael O. Rabin in 1981
- Classified as a cryptographic primitive used as a building block for complex cryptosystems
- Has 9 Wikipedia language editions (ca, en, es, fr, he, ja, pl, ru, zh)
- Has a BabelNet ID of 03357042n
- Has a Freebase ID of /m/02pfp4
- Part of the cryptographic primitive class
- Related to cryptography and indistinguishability obfuscation
- Has 9 sitelinks across Wikimedia projects

## FAQs
### Q: What is oblivious transfer used for?
A: Oblivious transfer is used as a fundamental building block in more complex cryptosystems, enabling secure protocols where one party can transfer information to another without learning which specific piece was received.

### Q: Who invented oblivious transfer?
A: Michael O. Rabin invented oblivious transfer in 1981, establishing it as a foundational concept in cryptography.

### Q: Is oblivious transfer a complete cryptographic system?
A: No, oblivious transfer is classified as a cryptographic primitive rather than a complete system - it serves as a building block that other cryptographic protocols are built upon.

## Why It Matters
Oblivious transfer represents a fundamental breakthrough in cryptography that enables privacy-preserving information exchange. By allowing one party to send information to another without knowing what was received, it solves a critical problem in secure communication protocols. This primitive has become essential for building more complex cryptographic systems, including secure multi-party computation and zero-knowledge proofs. Its invention by Michael O. Rabin in 1981 marked a significant advancement in our ability to design protocols where parties can interact while maintaining strict privacy guarantees. The protocol's importance extends beyond theoretical cryptography into practical applications where information asymmetry and privacy are paramount concerns.

## Notable For
- First proposed by Michael O. Rabin in 1981, establishing a new category of cryptographic protocols
- Serves as a foundational building block for complex cryptosystems and secure multi-party computation
- Enables privacy-preserving information exchange where the sender doesn't learn what the receiver obtained
- Classified as a cryptographic primitive with applications across multiple areas of cryptography
- Has maintained relevance for over four decades as a core concept in modern cryptographic protocol design

## Body
### Historical Development
Oblivious transfer was introduced by Michael O. Rabin in 1981, representing a novel approach to secure information transfer. The protocol allows a sender to provide multiple pieces of information to a receiver in such a way that the receiver obtains exactly one piece, but the sender remains unaware of which piece was received.

### Technical Classification
As a cryptographic primitive, oblivious transfer occupies a fundamental position in the hierarchy of cryptographic tools. It is not a complete cryptosystem but rather a building block that more complex protocols are constructed from. This classification reflects its role as a reusable component in various cryptographic applications.

### Related Concepts
The protocol is closely related to other areas of cryptography, particularly indistinguishability obfuscation, which deals with creating cryptographic algorithms that hide the structure of programs. Both concepts share the goal of enabling secure computation while preserving privacy.

### Implementation and Standards
While specific implementation details vary, oblivious transfer protocols have been standardized and referenced across multiple platforms. The protocol has BabelNet and Freebase identifiers, indicating its recognition in knowledge representation systems. Its presence across nine Wikipedia language editions demonstrates its international importance in the field of cryptography.

## References

1. [Source](http://www.iacr.org/museum/rabin-obt.html)
2. Freebase Data Dumps. 2013
3. BabelNet
4. [OpenAlex](https://docs.openalex.org/download-snapshot/snapshot-data-format)