Public key certificate EDS is a digital document confirming the correspondence between a public key and information identifying the owner of the key. It contains information about the owner of the key information about the public key, its purpose and scope, the name of the certification authority and so on. Each certificate can be also connected with a private key. Storage of certificates is called a certificate authority. Certificate store often contains numerous certificates, possibly derived from different CAs. Certificates in the repository into folders (categories) that have their own hierarchy. To access any certificate must specify the name of the repository (category), in which it is located. To create a digital signature private key is required. Certificates that contain private keys that are usually located in the two repositories - the repository of the current user or local computer store. To select the storage you want to use the property Use Local Machine Certificates. By default it is set to false, and the search is made in the certificate store of the current user (CERT_SYSTEM_STORE_CURRENT_USER). If it is set to true, the search will be made in the local computer store (CERT_SYSTEM_STORE_LOCAL_MACHINE).