MurmurHash is a non-cryptographic hash function suitable for general hash-based data structures like hash tables, bloom filters, and in various other algorithms where fast hashing with good distribution properties is required. Here are some detailed aspects of MurmurHash:
History and Development
- MurmurHash was originally designed by Austin Appleby in 2008, with the first version, MurmurHash2, released to address the deficiencies of existing hash functions at that time, particularly in terms of speed and collision resistance.
- Subsequent versions were developed to improve upon the original:
- MurmurHash2 - Improved distribution and speed.
- MurmurHash3 - Enhanced for better performance on 64-bit processors and better distribution.
- The development of MurmurHash was driven by the need for a hash function that could handle keys of any size, was fast, had a low collision rate, and was simple to implement.
Key Features
- Speed: MurmurHash is designed to be very fast, making it suitable for real-time applications.
- Distribution: It aims to provide a very uniform distribution of hash values, which is crucial for minimizing collisions in hash tables.
- Simplicity: The algorithm is relatively simple, which makes it easier to implement and audit for security.
- Seedability: Allows for the use of a seed value to generate different hash values for the same input, useful in applications where hash collisions need to be minimized over time or across different systems.
Applications
- MurmurHash is widely used in:
- Hash tables in programming libraries like Google's LevelDB for key hashing.
- Distributed systems for consistent hashing.
- Database indexing where fast hash computation is necessary.
- Various other data structures where hash functions are utilized.
Notable Properties
- It is not designed to be cryptographically secure, meaning it should not be used for cryptographic purposes like digital signatures or password hashing.
- The hash function can be adapted to different sizes (32-bit or 64-bit), which offers flexibility depending on the application's needs.
External Resources
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