Editing One-time password (section)

=== Challenge–response ===
The use of [[challenge–response]] one-time passwords requires a user to provide a response to a challenge. For example, this can be done by inputting the value that the token has generated into the token itself. To avoid duplicates, an additional counter is usually involved, so if one happens to get the same challenge twice, this still results in different one-time passwords. However, the computation does not usually{{Citation needed|date=January 2010}} involve the previous one-time password; that is, usually, this or another algorithm is used, rather than using both algorithms.