Hello, In my project, we implement Alfresco Enterprise - v4.2.1. - For end-user, access to Alfresco (upload, delete…) is only possible with web services (CMIS : /alfresco/service/). There is no direct access to the UI (only for administration). - After an upload, link to the file is stored in an other tool. - There is no account for end-user in Alfresco (only for administration). Upload, delete… are performed with technical user.
As you are using alfresco 4.2 there is OOB feature for share documents. You can share/unshare from [strong]Share[/strong] interface, with that share url user can view/download file without authentication.