{"id":1541,"date":"2022-12-26T05:51:25","date_gmt":"2022-12-26T05:51:25","guid":{"rendered":"https:\/\/cwatch.comodo.com\/blog\/?p=1541"},"modified":"2022-12-26T08:35:35","modified_gmt":"2022-12-26T08:35:35","slug":"hashing-algorithm","status":"publish","type":"post","link":"https:\/\/cwatch.comodo.com\/blog\/website-security\/hashing-algorithm\/","title":{"rendered":"What is Hashing and How Does Hash Algorithm Works?"},"content":{"rendered":"

Hashing Definition: What is Hashing, Hash Techniques and Methods<\/h2>\n

What is Hashing? – The hashing algorithm<\/strong> is referred to as the hash function: a term probably derived from the concept that the resulting hash value can be assumed as a “mixed up<\/strong>” version of the represented value.<\/p>\n

Hashing refers to the transformation of a string of characters into a typically shorter fixed-length value or key that represents the original string. Hashing is apt for indexing and retrieving items in a database as it takes less time to find the item using the shorter hashed key in comparison to the time taken while using the original value. Hashing is also employed in several encryption algorithms.<\/p>\n

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Different Hashing Techniques<\/h2>\n

Three basic methods of dealing with hash clashes are available. They are:<\/p>\n

    \n<\/p>\n
    \n<\/p>\n
    \n
  1. Chaining<\/li>\n<\/div>\n<\/div>\n
    \n <\/p>\n
    \n
  2. Rehashing<\/li>\n<\/div>\n<\/div>\n
    \n <\/p>\n
    \n
  3. Separate chaining<\/li>\n<\/div>\n<\/div>\n<\/ol>\n<\/div>\n

    1.Chaining<\/h3>\n

    This hashing technique builds a link list of all items whose keys possess the same value. During a search, this sorted linked list is sequentially traversed from the desired key. It involves adding a link field to each table position. There are three types<\/strong> of chaining:<\/p>\n

    General Coalesced Hashing<\/em><\/h4>\n

    This is the generalization of the standard coalesced chaining method. In this method, extra positions are added to the hash table that can be employed for listing the nodes at the time of collision.<\/p>\n

    Standard Coalesced Hashing<\/em><\/h4>\n

    This is considered to be the simplest of all chaining methods<\/strong>. It brings down the average number of probes for an unsuccessful search. It also executes the deletion without causing any negative impact on efficiency.<\/p>\n

    Varied Insertion Coalesced Hashing<\/em><\/h4>\n

    This chaining type is the combination of general and standard coalesced hashing<\/strong>. In this method, the colliding item is inserted into the list instantly following the hash position unless the list developing from that position contains a cellar element.<\/p>\n

    2.Rehashing<\/h3>\n

    This hashing technique deals with using a secondary hash function. The rehash function is successively applied until an empty position is identified in the table where an item can be inserted. The rehash function is again used to locate the item if the item\u00e2\u20ac\u2122s hash position is found to be occupied during the search.<\/p>\n

    3.Separate Chaining<\/h3>\n

    It is not possible to insert items more than the table size. In certain cases, space much more than required is allocated leading to space wastage. To handle these issues, a method called separate chaining is available for resolving clashes. This hashing technique<\/strong> maintains a separate link list for all records whose keys hash into a specific value. As part of this method, the items ending with a specific number are placed in a particular link list. The 10’s and 100’s are not taken into account. The pointer to the node points to the next node, and the pointer points to the NULL value<\/strong> in instances when there are no more nodes. A few key benefits of this separate chaining method include:<\/p>\n