A method for timestamping digital images used to establish that a digital image was acquired after a first date designated post-date and before a second date designated ante-date, comprising the following steps: - Generating by a first computer server, before the post-date, of a code unknown in advance. - Sending by the first computer server, on the post-date, of the code unknown in advance. - Storage by said first computer server of an association (C+P) between the post-date and said code unknown in advance. - (i) Reception by a second computer server, on the ante-date, of the joint digital image of a subject and a representation of the code unknown in advance, which representation of the code unknown in advance is printed, written or projected on the subject or on one or more objects such that at least one representation of the unknown, written or projected code unknown in advance is contained in the field of view of said joint digital image, and calculation of a digital fingerprint of the digital image, Or (ii) Reception by the second computer server, on the ante-date, of a digital fingerprint of the joint digital image of a subject and a representation of the code unknown in advance, which representation of the code unknown in advance is printed, written or projected onto the subject or onto one or more objects such that at least one printed, written or projected representation of the code unknown in advance is contained in the field of view of said joint digital image. - Storage by the second computer server of one correspondence (EIN + A) of the digital fingerprint and the ante-date. - A reception step that is executed after storage of the correspondence (EIN + A) between the digital fingerprint and the ante-date, and is performed by a third server having access to the database of the second server, said reception step comprising the following sub-steps: - Reception of a second digital image and calculation of a second digital fingerprint, or alternatively, direct reception of a second digital fingerprint of a second digital image. - Search for the second digital fingerprint in the database of the second computer server. - In case the second digital fingerprint corresponds (EIN2=EIN) to the stored digital fingerprint, transmission of the ante-date corresponding to the association between the digital fingerprint and the stored ante-date. - Generating by a first computer server, before the post-date, of a code unknown in advance. - Sending by the first computer server, on the post-date, of the code unknown in advance. - Storage by said first computer server of an association (C+P) between the post-date and said code unknown in advance. - (i) Reception by a second computer server, on the ante-date, of the joint digital image of a subject and a representation of the code unknown in advance, which representation of the code unknown in advance is printed, written or projected on the subject or on one or more objects such that at least one representation of the unknown, written or projected code unknown in advance is contained in the field of view of said joint digital image, and calculation of a digital fingerprint of the digital image, - Storage by the second computer server of one correspondence (EIN + A) of the digital fingerprint and the ante-date. - A reception step that is executed after storage of the correspondence (EIN + A) between the digital fingerprint and the ante-date, and is performed by a third server having access to the database of the second server, said reception step comprising the following sub-steps: - Reception of a second digital image and calculation of a second digital fingerprint, or alternatively, direct reception of a second digital fingerprint of a second digital image. - Search for the second digital fingerprint in the database of the second computer server. - In case the second digital fingerprint corresponds (EIN2=EIN) to the stored digital fingerprint, transmission of the ante-date corresponding to the association between the digital fingerprint and the stored ante-date.