title: Which public key (SP or remote IDP) to use while signing SAML request
body: <p>I am trying to configure my application (SP) to work with remote IDP. The IDP provided me with a certificate to configure with SP. For SAML request, do I use SP's public key or IDP's? 
  Also, where can I find good resources to study SAML in detail (apart from the oasis formal documents). The tutorials that I find are very simplistic (i.e. they just describe that SP goes to IDP and then it is redirected back but do not go into detail on SAML messages). The oasis documents are confusing.
  Thanks for any answers</p>