1. A method for releasing a secured document from a document security system, the method comprising: receiving a request from a user affiliated with an organization to release a secured document including a security information portion and a data portion from the document security system, to an external user unaffiliated with the organization, wherein the document security system is associated with the organization, and wherein the security information portion includes a file key and access control restrictions pertaining to the data portion; in response to receiving the request: obtaining a public key associated with the external user; encrypting the data portion of the secured document using the file key; encrypting the security information portion of the secured document, including the file key, using the public key associated with the external user; imposing the access control restrictions by including access rules in the security information portion, wherein the access rules are defined in a markup language and limit a type, a location, and an extent of access that the external user is granted with respect to the secured document, the location of access being one of within the organization or outside of the organization; and releasing the secured document including the encrypted file key to the external user.