php - How to prevent reuse of password hash by another user -

i need prevent reuse of password hash user, example if user can create hash (knowing password of curse) if gained access database , replace else's hash his, able log in user wondering if adding id of user hash practice, if not, else can do? thank you.

if can substitute credentials in database, and if thing determines access system, then, yes, user can cause system accept whatever password chooses.

this 1 important reason why many production systems ... used within company ... and many of back-side "plumbing" layers of public-facing systems ... not use passwords of sort handle authentication or authorization. instead, use "trusted third-party authority" techniques such ldap (opendirectory) or kerberos. no 1 "whispering magic-words 1 another" @ point.

in scenario, both "authentication" (verifying requesting user is), , "authorization" (establishing can do) not handled logic within systems themselves: these tasks delegated centrally managed corporate authority. there concept of "single sign-on." there no "passwords" steal. if system requires user respond personal-challenge, e.g. enter password part of procedure, central authority (software layer) manages everything: providing challenge, interpreting response, knowing correct response timely given, , forth.

these robust technologies peer-reviewed, trustworthy implementations cross-platform , industry standard. they're comprehensive. when "swipe badge" building every morning, they're unlocks door. can accessed php, and/or whatever web-server service running php application.