BIKE - Quantum-Safe Key Exchange

BIKE (Bit Flipping Key Encapsulation) is a code-based key encapsulation mechanism designed to be secure against quantum computer attacks.

Key Generation

Generate a BIKE key pair for key encapsulation

Encrypt File

Upload a file and encrypt it with recipient's public key

Decrypt File

Upload an encrypted file and decrypt it with your private key

About BIKE

BIKE (Bit Flipping Key Encapsulation) is a code-based key encapsulation mechanism (KEM) designed to be secure against attacks from quantum computers. It was an alternate candidate in the NIST Post-Quantum Cryptography standardization process.

Key Features:
  • Type: Code-based key encapsulation mechanism (KEM)
  • Security Basis: Quasi-Cyclic Moderate Density Parity-Check (QC-MDPC) codes
  • Quantum Resistance: Designed to be secure against quantum computer attacks
  • Key Sizes: Relatively compact compared to other code-based schemes
  • Performance: Efficient key generation, encapsulation, and decapsulation operations
How BIKE Works:
  1. Key Generation:
    • Generate two sparse binary polynomials h₀ and h₁
    • Compute h = h₁ · h₀⁻¹ in a polynomial ring
    • Public key: h
    • Private key: (h₀, h₁)
  2. Encapsulation (Generating a Shared Secret):
    • Generate a random error vector e
    • Compute the syndrome s = h · e
    • Derive a shared secret K from e
    • Ciphertext: s
  3. Decapsulation (Recovering the Shared Secret):
    • Use the private key to decode the syndrome s and recover e
    • Derive the same shared secret K from e
Security and Advantages:
Feature Description
Security Basis Based on the hardness of decoding random linear codes, a problem believed to be resistant to quantum attacks
Key Size Smaller public and private keys compared to some other post-quantum schemes
Performance Efficient operations suitable for various applications, including constrained environments
Implementation Relatively simple implementation with potential for optimization
Variants and Parameters:
  • BIKE-1: Designed for NIST Security Level 1 (equivalent to AES-128)
  • BIKE-3: Designed for NIST Security Level 3 (equivalent to AES-192)
  • BIKE-5: Designed for NIST Security Level 5 (equivalent to AES-256)
Applications:
  • Key Exchange: Establishing shared secrets for symmetric encryption
  • Hybrid Cryptography: Combining with classical algorithms for transition to post-quantum security
  • TLS and Secure Communications: Potential use in future quantum-resistant communication protocols
Note: While BIKE was not selected as a primary standard by NIST, it remains a promising post-quantum algorithm with ongoing research and development. Its code-based approach provides diversity in post-quantum cryptography, complementing other approaches like lattice-based cryptography (e.g., Kyber).