The invention is a method for securely accessing a document in paper form containing a set of data by a user. The method comprises the following steps: (a) from a current version of the document, detecting the existence of a target data belonging to an enhanced version of the document and missing from the current version of the document, (b) generating a link value allocated to the target data by applying a preset function to a subset of said set of data, (c) retrieving a metadata from a secure storage unit by using the link value and, using a message based on said metadata, proposing to the user to get the target data, (d) getting both agreement of the user and credentials of the user, (e) generating a request by using the link value and said credentials for retrieving the target data from the secure storage unit only if the user gave his agreement, (f) providing the user with the target data only if the secure storage unit successfully checked the compliance of the request with preset access rules.