The paper introduces Cuckoo Hashing, a simple and efficient dictionary data structure that achieves worst-case constant lookup time, matching the theoretical performance of the classic dynamic perfect hashing scheme by Dietzfelbinger et al. The space usage is comparable to that of binary search trees, with an average of three words per key. The authors provide a detailed analysis of the algorithm, showing that it has the same theoretical properties as the dynamic dictionary, including worst-case constant lookup time and amortized constant update time. The practicality of Cuckoo Hashing is demonstrated through extensive experiments and comparisons with other well-known hashing methods, such as chained hashing, linear probing, and double hashing. The experiments show that Cuckoo Hashing is competitive, especially when the dictionary fits in cache, making it attractive for practical use where a worst-case guarantee on lookups is desired. The paper also discusses the implementation details, hash function choices, and the impact of different hash functions on performance.The paper introduces Cuckoo Hashing, a simple and efficient dictionary data structure that achieves worst-case constant lookup time, matching the theoretical performance of the classic dynamic perfect hashing scheme by Dietzfelbinger et al. The space usage is comparable to that of binary search trees, with an average of three words per key. The authors provide a detailed analysis of the algorithm, showing that it has the same theoretical properties as the dynamic dictionary, including worst-case constant lookup time and amortized constant update time. The practicality of Cuckoo Hashing is demonstrated through extensive experiments and comparisons with other well-known hashing methods, such as chained hashing, linear probing, and double hashing. The experiments show that Cuckoo Hashing is competitive, especially when the dictionary fits in cache, making it attractive for practical use where a worst-case guarantee on lookups is desired. The paper also discusses the implementation details, hash function choices, and the impact of different hash functions on performance.