The output from a hash function is referred to as the hash value, hash code, hash sum, checksum or just plain "hash" as in "the hash of the file is...". Generally a hash function is presumed to be secure or it wouldn't be used. If a hash is not secure it could be referred to as "worthless" or "false sense of security".

hash key is an element in the hash table. it is the data that you will combine (mathematical) with hash function to produce the hash.

hash function is technique used in message authentication it is attached to the message for security purpose

Insertion in hash tables is based on a 'key' value which is calculated on the basis of a hash function.

This hash function generates the key based on what type of data it is fed.

For example hash function for an integer input might look like this :

int hash(int val)

{

return (val%101);

}

where return value of hash function would become a key.

Complete implementation can be found at: http://simplestcodings.blogspot.com/2010/07/hash-table.html

if collision is occurred in hash function then we can solve this problem by using double hash function