Need to login to other salesforce Instance from your own Instance ? Here is a simple solution. Decide service provider and Identity provider Service Provider : Salesforce Instance (A's developer org). Identity Provider : Salesforce Instance (B's developer org). Identity provider Step 1 : Create and register a domain in Identity provider organization, (Domain Management --> B's Domain) Step 2 : Enable Identity provider. (Security Controls --> Identity Provider) Create a dummy certificate (self Signed) and set it as use on communication with service provider . Save identity provider settings. Download the certificate and saved in a drive.( Need to upload in service provi...