Hashing

Producing hash values for accessing data or for security. A hash value (or simply hash), also called a message digest, is a number generated from a string of text. The hash is substantially smaller than the text itself, and is generated by a formula in such a way that it is extremely unlikely that some other text will produce the same hash value.

Hashes play a role in security systems where they’re used to ensure that transmitted messages have not been tampered with. The sender generates a hash of the message, encrypts it, and sends it with the message itself. The recipient then decrypts both the message and the hash, produces another hash from the received message, and compares the two hashes. If they’re the same, there is a very high probability that the message was transmitted intact.

Hashing is also a common method of accessing data records. Consider, for example, a list of names:

  • John Smith
  • Sarah Jones
  • Roger Adams
  • To create an index, called a hash table,for these records, you would apply a formula to each name to produce a unique numeric value. So you might get something like:

  • 1345873 John smith
  • 3097905 Sarah Jones
  • 4060964 Roger Adams
  • Then to search for the record containing Sarah Jones,you just need to reapply the formula, which directly yields the index key to the record. This is much more efficient than searching through all the records till the matching record is found.

    Vangie Beal
    Vangie Beal
    Vangie Beal is a freelance business and technology writer covering Internet technologies and online business since the late '90s.

    Related Articles

    Phishing

    What is phishing? Phishing is a type of cybercrime in which victims are contacted by email, telephone, or text message by an attacker posing as...

    Photo Editing Software

    Photo editing software is used to manipulate or enhance digital images. This category of software ranges from basic apps, which are able to apply...

    SOHO Business Solutions: Free Email Marketing Services

    Just like big businesses, SOHO (small office/home office) owners can leverage email marketing systems to communicate with customers, partners and employees. Just like big businesses,...

    Fintech

    Fintech, also known as "financial technology," is a term used to describe companies that use innovative technology to create more efficient, transparent, and cost-effective...

    ScalaHosting

    ScalaHosting is a leading managed hosting provider that offers secure, scalable, and affordable...

    HRIS

    Human resources information system (HRIS) solutions help businesses manage multiple facets of their...

    Best Managed Service Providers...

    In today's business world, managed services are more critical than ever. They can...