Computer-implemented method for the secure preparation of a property transfer document

1 . A computer-implemented method for preparing a property transfer document, comprising:

acquiring a plurality of data entered one after the other by a user, each acquired datum corresponding to an item of information on said document, the acquired data including at least information that identifies the property and at least information related to at least one condition of the property;

creating an entry log forming a chronological sequence of the entry of the data by said user;

an incremental security key computing step in which a first security key is computed during the acquisition of a first datum entered by said user and, for each acquisition of a subsequent datum entered by the user, a subsequent security key is computed on the basis of said entered datum and of the preceding security key until a final security key is computed;

storing said acquired data, said entry log and said security keys, said security keys computed in the incremental security key computing step being stored in a sequential manner so as to form an incremental security key log;

creating the property transfer document based on the acquired data, which includes at least the acquired data; and

digitally publishing the property transfer document.

2 . The computer-implemented method as claimed in claim 1 , wherein the method comprises, after the creating the entry step, constituting a first security key log such that, for each entry in the entry log, the first security key log comprises a key computed on the basis of said entry.

3 . The computer-implemented method as claimed in claim 1 , wherein at least said final security key is stored in a decentralized manner, in particular in a blockchain.

4 . The computer-implemented method as claimed in claim 1 , wherein the acquiring-comprises the acquisition of at least one item of multimedia content associated with a distinct fingerprint computed by way of a fingerprint computation distinct from the other acquired data and/or stored in a multimedia content fingerprint log distinct from the other acquired data.

5 . A computer-implemented authentication method for verifying the authenticity of a document prepared by,

acquiring a plurality of data entered one after the other by a user, each acquired datum corresponding to an item of information on said document, and the acquired data including at least information that identifies the property and at least information related to at least one condition of the property;

creating an entry log forming a chronological sequence of the entry of the data by said user;

an incremental security key computing step in which a first key is computed during the acquisition of a first datum entered by said user and, for each acquisition of a subsequent datum entered by the user, a subsequent security key is computed on the basis of said entered datum and of the preceding security key until a final security key is computed;

storing said entry log;

storing said acquired data;

storing said security keys, said security keys computed in the incremental security key computing step being stored in a sequential manner so as to form an incremental security key log;

creating the property transfer document based on the acquired data, which includes at least the acquired data; and

digitally publishing a property transfer document according to the acquired data, the authentication method comprising:

acquiring said stored acquired data, said stored security keys, and said stored entry log;

computing a final authentication security key on the basis of said stored entry log and of said stored acquired data, the final authentication security key being computed by an incremental authentication security key computing step, wherein a first authentication key is computed based on a first stored datum, and for each subsequent stored datum, a new authentication key is computed based on said datum and the immediately preceding authentication key, until the final authentication security key is obtained;

comparing said stored final security key and the final authentication security key; and

verifying that said prepared document is authentic if the stored final security key and the final authentication security key are identical.

6 . The computer-implemented method as claimed in claim 4 , wherein the at least one item of multimedia content is a digital image.

7 . The computer-implemented method as claimed in claim 4 , wherein the at least one item of multimedia content is a digital video.

8 . A data-processing device comprising a computer that is configured to implement the steps of a computer-implemented method for preparing a property transfer document or a computer-implemented authentication method for verifying the authenticity of a document prepared by a preparation method, or a computer product comprising a non-transitory computer-readable medium storing a computer program comprising instructions which, when executed by a computer, result in the computer implementing the steps of the computer-implemented method for preparing a property transfer document or the computer-implemented authentication method for verifying the authenticity of a document prepared by the preparation method, the computer-implemented method for preparing a property transfer document, comprising:

acquiring a plurality of data entered one after the other by a user, each acquired datum corresponding to an item of information on said document, the acquired data including at least information that identifies the property and at least information related to at least one condition of the property;

creating an entry log forming a chronological sequence of the entry of the data by said user;

an incremental security key computing step in which a first security key is computed during the acquisition of a first datum entered by said user and, for each acquisition of a subsequent datum entered by the user, a subsequent security key is computed on the basis of said entered datum and of the preceding security key until a final security key is computed;

creating the property transfer document based on the acquired data, which includes at least the acquired data; and digitally publishing the property transfer document, and

the authentication method comprising:

acquiring said acquired data, said security keys, and said entry log;

computing a final authentication security key on the basis of said entry log and of said acquired data, the final authentication security key being computed by an incremental authentication security key computing step, wherein a first authentication key is computed based on a first stored datum, and for each subsequent stored datum, a new authentication key is computed based on said datum and the immediately preceding authentication key, until the final authentication security key is obtained;

comparing said stored final security key and the final authentication security key; and

verifying that said prepared document is authentic if the stored final security key and the final authentication security key are identical.