The most frequent types of authentication available in use for authenticating online users differ in the level of security provided by combining factors from the one or more of the three categories of factors for authentication: As the weakest level of authentication, only a single component from one of the three categories of factors is used to authenticate an individual’s identity.
The use of only one factor does not offer much protection from misuse or malicious intrusion.
With software, companies have taken great steps to protect from counterfeiters, including adding holograms, security rings, security threads and color shifting ink.
The ways in which someone may be authenticated fall into three categories, based on what are known as the factors of authentication: something the user knows, something the user has, and something the user is.
Each authentication factor covers a range of elements used to authenticate or verify a person's identity prior to being granted access, approving a transaction request, signing a document or other work product, granting authority to others, and establishing a chain of authority.
Security research has determined that for a positive authentication, elements from at least two, and preferably all three, factors should be verified.
Consumer goods such as pharmaceuticals, perfume, fashion clothing can use all three forms of authentication to prevent counterfeit goods from taking advantage of a popular brand's reputation (damaging the brand owner's sales and reputation).
As mentioned above, having an item for sale in a reputable store implicitly attests to it being genuine, the first type of authentication.
These external records have their own problems of forgery and perjury, and are also vulnerable to being separated from the artifact and lost.
In computer science, a user can be given access to secure systems based on user credentials that imply authenticity.
In computer science, verifying a person's identity is often required to allow access to confidential data or systems.
Authentication can be considered to be of three types: The first type of authentication is accepting proof of identity given by a credible person who has first-hand evidence that the identity is genuine.
Certificates can, however, also be forged, and the authentication of these poses a problem.