As more and more organizations move away from paper and find alternative electronic methods, signing documents will also need to be replaced with a viable solution. PKI [1] can be used in different types of electronic environments to help eliminate paper. One common usage for this method is with digital signatures. This type of signature provides a secure method for signing and approving electronic documents, forms, files and other data types requiring a signature.
In a PKI digital signature environment, there are two types of electronic keys required. The first type is called a private key and held by the person, who will be attaching their signature to various electronic data types. The other type is called a public key, and is needed by anyone wanting to authenticate the signature. In order to verify authenticity, organizations often use a trusted third party to create these keys on their behalf.
Links:
[1] http://www.digi-sign.com/digi-access