An increase in network technology development has its own downside; thus as more connections are established with various global computer networks daily, the more exposed the connected systems are to unauthorized access, thus making security of data very important to address. Internet based transaction applications such as internet banking, online shopping, etc., involves sharing of very sensitive information between two or more parties that should be confidential. This requires very secure end-to-end connections that will ensure the data integrity, confidentiality, authenticity, etc. Cryptography is one of the most reliable and best, if not the best way to keep sensitive data from unauthorized users. This implies a good cryptosystem that maximizes security of the information been transferred and minimizes a substantial amount of delay time is needed. This is dependent on the particular cryptosystem one chooses to secure information. Also of the two known types of cryptosystems, the best in security is asymmetric cryptosystems, which uses two different keys; one for encryption and the other for decryption, whiles symmetric cryptosystems use the same key for both encryption and decryption. The essential features of asymmetric cryptosystems that determines their efficiency and security are; encryption computation time, decryption computation time, performance, encryption throughput, decryption throughput, throughput, randomness, key length and Operation per Instruction (O/I). This research seeks to examine these properties of some asymmetric cryptosystems and subsequently develop a proposed cryptosystem that is more secure and efficient. The results of this research clearly demonstrate that, the proposed cryptosystem has better results for all the properties stated above.

No abstract

How to store information for it to be searched and retrieved efficiently is one of the fundamental problems in computer science. There exists sequential search that support operation such as INSERT, DELETE and RETRIVAL in O (n log (n)) expected time in operations. Therefore in many applications where these operations are needed, hashing provides a way to reduce expected time to O (1).There are many different types of hashing algorithms or functions such as cryptographic hash functions, non-cryptographic hash function, checksums and cyclic redundancy checks. Non-cryptographic hash functions (NCHFs) take a string as input and compute an integer output (hash index) representing the position in memory the string is to be stored. The desirable property of a hash function is that the outputs are evenly distributed across the domain of possible outputs, especially for inputs that are similar. Noncryptographic hash functions have an immense number of applications, ranging from compilers and databases to videogames, computer networks, etc. A suitable hash function and strategy must be used for specific applications. This will help efficient use of memory space and access time. The most essential features of non-cryptographic hash functions is its % distribution, number of collisions, performance, % avalanche and quality which are the properties of the hash function. Basing on the properties assessed using a test suite; the results clearly demonstrated that: the proposed hash function that was developed had better properties as compared to other hash functions.