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9.7.3 Security Concerns with Weak Hash Functions

Weak hash functions can lead to predictable collisions, making systems vulnerable to

attacks. For example, in password storage, if a simple hash function is used, attackers can

easily guess or precompute hash values. Cryptographic hash functions (like SHA-256) are

required for security-sensitive applications.

Example: Weak Hash Function in C++

This example shows how two different strings can produce the same hash value with

a weak function, leading to collisions and potential vulnerabilities.

9.8 Summary

In this chapter, we explored hashing as one of the most efficient techniques for data

storage and retrieval. We began with the definition and motivation behind hashing,

emphasizing its ability to provide constant-time average performance for insertion, deletion,

and search operations. We then studied hash functions, discussing the properties of good
functions, simple arithmetic-based methods (division and multiplication), and advanced

cryptographic functions used in security. Practical examples demonstrated how hash

functions distribute keys across a table.
Next, we examined the structure of hash tables, which combine arrays, hash

functions, and collision resolution strategies to store data efficiently. We implemented basic

operations such as insertion, deletion, and searching, and highlighted the importance of

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