# Supersingular Isogeny Key Encapsulation

> post-quantum cryptographic algorithm

**Wikidata**: [Q17085253](https://www.wikidata.org/wiki/Q17085253)  
**Wikipedia**: [English](https://en.wikipedia.org/wiki/Supersingular_isogeny_key_exchange)  
**Source**: https://4ort.xyz/entity/supersingular-isogeny-key-encapsulation

## Summary
Supersingular Isogeny Key Encapsulation (SIKE) is a post-quantum cryptographic algorithm designed for secure key transport over insecure channels. It functions as a specific subclass of key encapsulation mechanisms, utilizing the mathematical properties of supersingular isogeny graphs and supersingular elliptic curves. It is also known as Supersingular Isogeny Diffie–Hellman (SIDH).

## Key Facts
- **Classification:** Subclass of Key encapsulation.
- **Primary Function:** Cryptographic protocol for key transport over an insecure channel.
- **Field:** Facet of post-quantum cryptography.
- **Authors:** Luca De Feo and Plut Jao.
- **Initial Publication:** 2011.
- **Publication Venue:** Post-Quantum Cryptography - 4th International Workshop, PQCrypto 2011 (Taipei, Taiwan).
- **Mathematical Basis:** Uses supersingular isogeny graphs and supersingular elliptic curves.
- **Aliases:** SIDH, Supersingular isogeny Diffie–Hellman, SIKE, Supersingular isogeny key exchange.
- **Official Website:** https://sike.org/

## FAQs
### Q: What is Supersingular Isogeny Key Encapsulation (SIKE)?
A: SIKE is a post-quantum cryptographic algorithm used for key encapsulation. It allows two parties to transport a cryptographic key over an insecure channel using mathematics based on supersingular elliptic curves.

### Q: How does SIKE relate to standard Diffie–Hellman?
A: SIKE is also known as Supersingular Isogeny Diffie–Hellman (SIDH). It serves a similar function to traditional Diffie–Hellman protocols but utilizes different mathematical foundations intended to resist quantum computing attacks.

### Q: Who created SIKE and when was it introduced?
A: The algorithm lists Luca De Feo and Plut Jao as authors. It was initially published in 2011 at the 4th International Workshop on Post-Quantum Cryptography (PQCrypto 2011) in Taipei, Taiwan.

## Why It Matters
Supersingular Isogeny Key Encapsulation matters because it addresses the critical need for secure communications in the era of quantum computing. As a facet of post-quantum cryptography, SIKE provides a mechanism for key transport that is designed to withstand attacks that would defeat classical cryptographic systems. By relying on the complex mathematical structure of supersingular isogeny graphs and elliptic curves, it offers a distinct approach to securing data. Its introduction at PQCrypto 2011 marked a significant development in the search for quantum-resistant algorithms, providing a specialized protocol for encapsulating keys rather than just signing or hashing data. This capability is fundamental for establishing secure sessions and encrypting information in future digital infrastructure.

## Notable For
- Being a specialized **Key Encapsulation** mechanism, distinct from basic key exchange.
- Utilizing **supersingular isogeny graphs** and **supersingular elliptic curves** as its mathematical foundation.
- Classification as a **post-quantum cryptographic** algorithm.
- Having an official dedicated resource and website (sike.org).
- Early introduction in the field (2011) compared to other post-quantum standards.

## Body
### Classification and Function
Supersingular Isogeny Key Encapsulation (SIKE) is a cryptographic protocol classified as a subclass of **Key encapsulation**. Its primary purpose is to facilitate **key transport over an insecure channel**. Unlike general encryption schemes, key encapsulation is specifically designed to securely transmit a symmetric key, which is then used for subsequent data encryption.

### Mathematical Foundation
The security and operation of SIKE rely on advanced mathematical structures. Specifically, the algorithm utilizes:
*   **Supersingular isogeny graphs**
*   **Supersingular elliptic curves**

These mathematical constructs are central to its function as a post-quantum cryptographic tool.

### History and Authorship
The foundational work for Supersingular Isogeny Key Encapsulation was established in **2011**.
*   **Authors:** The algorithm is attributed to **Luca De Feo** and **Plut Jao**.
*   **Publication:** The initial paper, referenced at `http://eprint.iacr.org/2011/506.pdf`, was presented at the **Post-Quantum Cryptography - 4th International Workshop, PQCrypto 2011**.
*   **Location:** The workshop took place in Taipei, Taiwan, from November 29 to December 2, 2011.

### Identity and Resources
SIKE is known by several aliases and is documented across various platforms.
*   **Aliases:** Supersingular isogeny Diffie–Hellman (SIDH), Supersingular isogeny Diffie–Hellman key exchange, and supersingular isogeny key exchange.
*   **Website:** The project maintains an official presence at `https://sike.org/`.
*   **Wikipedia Title:** Supersingular isogeny key exchange.