Patent Publication Number: US-2023139878-A1

Title: System and method for providing persistent authenticatable non-fungible token

Description:
FIELD OF THE DISCLOSURE 
     The present disclosure relates to digital certification and authentication of digital, physical, and intangible objects, and more specifically, to methods and systems for long-term authentication of non-fungible tokens (NFTs) secured on a blockchain. 
     BACKGROUND 
     A blockchain is a peer-to-peer, electronic ledger which is implemented as a computer-based decentralized, distributed computer-implemented system. A blockchain is made up of a number of individual blocks which, in turn, generally include some number of transactions. Each transaction is a data structure that encodes the transfer of control of a digital asset between participants in the blockchain computer-implemented system, and includes at least one input and at least one output. Each block contains a hash of the previous block so that blocks become chained together to create an extremely modification-resistant record of all transactions which have been written to the blockchain since its inception. 
     For a transaction to be written to the blockchain, it must be “validated.” Generally, network nodes, each storing a copy of the entire blockchain electronic ledger, arrive at a consensus via a consensus mechanism that is based on the rules of the specific blockchain. For the consensus mechanism, miners, stakeholders, or other suitable mechanism performs a process that ensures that each transaction contained in a new block is valid and that invalid transactions are rejected. For example, in order for a transaction to be written to the blockchain it will go through the following steps: i) be validated by the first node that receives the transaction—if the transaction is validated, the node relays it to the other nodes in the network; and ii) added to a new block built by a miner; and iii) mined, i.e., added to the public ledger of past transactions. 
     The primary area of blockchain-related interest is the use of “tokens” to represent and transfer assets via the blockchain. A token serves as an identifier that allows an object, such as a physical item, digital item, intangible asset, or other asset, to be referenced on the blockchain. Similar to physical assets, the tokens that represent them may have many properties, one of which is fungibility or non-fungibility. Fungible tokens (FT) are uniform, that is, tokens of the same type are identical and are divisible into smaller amounts. As such, a fraction of an FT can be transferred between users. Non-fungible tokens (NFTs), however, cannot be replaced with other tokens of the same type. NFTs represent non-fungible assets, such as assets possessing one or more unique features or characteristics that differentiates the asset from others of the same type. For example, while plane tickets from and to a same destination may look the same, each one has a different passenger name, seat number, etc., and, therefore, is unique. As such, each NFT is unique and differs from other tokens of the same class. Further, in contrast with FTs, NFTs cannot be divided, the elementary unit of the NFT being the token itself. 
     As an Example, the Ethereum blockchain has implemented the use of a new token standard called ERC-721 for tracking unique digital assets. The ERC-721 is a standard interface used to create, track and manage non-fungible tokens in the Ethereum blockchain. In ERC-721, each token is completely unique and non-interchangeable with other tokens, and thus non-fungible. NFTs allow developers to tokenize ownership of any arbitrary data, drastically increasing the design space of what can be represented as a token on the Ethereum blockchain. The popularity of such tokens has increased exponentially in recent years and correspondingly the prices that collectors are willing to pay have exploded. As of the date of this Application, the ERC-721 token for EtherRock 96 (a digital image of a rock) was purchased for 599 Ether (approximately valued at $2,262,003 at the time of sale). Clearly, additional improvements to the growing field of NFTs and blockchain would be welcome. 
     SUMMARY 
     Embodiments of the disclosure are directed to systems and methods for establishing the long-term authenticity of non-fungible tokens (NFT) minted on a public blockchain. In particular, various embodiments of the disclosure are directed to systems and methods for minting an NFT to possess, in addition to the typical digital signature produced via a public/private key pair, additional composition such that the NFT is object agnostic and persistently authenticatable across long spans of time. For example, various embodiments provide for systems and methods that establish the long-term authenticity of NFTs regardless as to whether the NFT is associated with a digital object, physical object, or intangible object, such as intellectual property assets, contracts, or other intangible assets, and allow for authentication in a variety of scenarios, such as when the associated object is not directly derived from the private key. 
     While it is generally the case that an NFT will be preserved on a public blockchain via a network of nodes and secured via the blockchain&#39;s consensus mechanism, such as proof of work, proof of stake, or other suitable consensus mechanism, there is no assurance that the NFT itself will preserve its ability to authenticate an associated object or its association with that object, particularly over long or very long periods of time. For example, traditional NFTs can typically only be authenticated against the possession of a private key via a public/private key pair. And while in some specific scenarios this information alone may be sufficient to authenticate the NFT, in many instances the NFT at least partially relies on one or more third parties to establish its association with a specific object. For example, often this responsibility is left to third party NFT exchanges, centralized databases, the private key holder, or to other entities. 
     As such, while there may be a high confidence in the ability of a blockchain to preserve and store the public key and digital signature information of the NFT along with any subsequent transaction data over long and very long periods of time—a blockchain cannot preserve information which the NFT does not itself include. As such, in many instances the blockchain will not preserve the linkage between the pseudo-anonymous public key or digital signature to the actual identity of the NFT minter. Further in many instances the blockchain will not preserve the association of the NFT with the object. And still further in many instances it will not contain enough information to ensure that the minter of the NFT was the originator or possessor of the object at the time of minting or had authority to mint the NFT on behalf or on the instructions of the originator or possessor of the object. 
     This is particularly a concern with regard objects that possess significant pre-blockchain history. In many instances, the pre-blockchain history is not maintained on the blockchain. This history is important to assist in independently verifying the authenticity of the NFT. Further, with regard to physical objects, such as physical art, or real estate, there is no information or documentation regarding appraised value or origin. In addition, with regard to physical objects the unique features that identify the specific object are not necessarily independently linked to the NFT. For digital objects the source construction resources and files are not linked and there are no certifications of authenticity or origin. Further, for digital NFTs, the ownership of the NFT or indication that the NFT was rightfully minted is not assured at the time of creation. 
     In addition, there is further concern with regard to intangible objects or other objects that possess contractual obligations or rights associated with their use. For example, for physical objects, the contracts, copyrights, rights for derivative works, etc. that exist have not been included at the time of minting. For digital objects, the rights to display, make derivative works, etc., are not established at the time of minting. Further, rights for use of the NFT itself are not clearly defined. Still further, with regard to both physical and digital objects, the NFT provides no assurance of long-term storage of the associated object. Since most objects exist “off-chain” the long-term storage of these assets must be persistent to ensure long-term value. Finally, NFTs currently provide insufficient acknowledgement and disclosure of smart contracts. For example, terms that will be auto-executed on the blockchain may not be disclosed. For example, any terms that relate to future resale of the NFT, royalties, or the like. In instances where such terms are included in the NFT they are not necessarily formatted into a human readable and comprehensive list of terms. Also, when minting a “Back to Physical” NFT, the authenticity of the physical object must be assured and links to the parent NFT must be authenticatable. 
     As such, typical NFTs fail to possess sufficient composition in order to ensure that the minted NFT is authenticatable and persistent across time. In particular, none of the existing NFTs are minted with composition to ensure their authentication particularly with regard to items with physicality, or items that were not directly derived from the private key holder. 
     While relying on third parties to store and/or authenticate this information may not pose a significant risk over short periods of time, information can easily degrade over long enough periods of time. For example, third-party exchanges and centralized databases may suddenly cease to exist or the data which they store may become lost or compromised. As a result, the information relied on to tie the NFT to the object or to the identity of the minter can be lost. As such, over several decades or even over centuries the owner of an NFT, their descendants, and others may find it difficult to discern whether an NFT is authentic or what object the NFT is associated with, the pre-blockchain history, any contractual obligations or rights associated with the corresponding object, and even the location where the object itself is located. Without addressing these issues the long term value of NFTs will suffer. 
     As such, embodiments of the disclosure are directed to systems and methods for establishing the long-term authenticity of NFTs when minted on a public blockchain. In order to solve the technical problems for described above, embodiments will define the structure, composition and process of an authenticatable and persistent NFT to establish and maintain long-term value. This structure and composition is applied during the minting process of the NFT to ensure that the NFT is not corrupted, incomplete, or ambiguous. In various embodiments, a signed certificate from a trusted authority will be generated as evidence that this process has been properly performed. 
     One or more embodiments provide benefits in the form of a system and method for digital token based authentication of unique objects that allows for long term storage of authenticating tokens within a blockchain over decades or even centuries, so long as the blockchain itself remains in operation. Further, various embodiments provide benefits in that it generates long-term authenticatable NFTs on a public blockchain where the private key can be held by a third party or generated by a third party with permission while still allowing the NFT holder to verify its authenticity as to the source of the NFT. Such benefits are expected to be particularly useful as services and industry around NFTs and blockchain tokens develop where a private key is stored on behalf of the creator/owner of the object or the NFT is created by the third party on behalf of the creator/owner. In particular various embodiments of the disclosure provide benefits for minting, establishing, and maintaining long-term NFTs that are object agnostic. For example, various embodiments ensure long term authentication of NFTs that are associated with physical objects, sometimes referred to as a “Digital Twin”, or NFTs that are associated with digital objects or intangible assets. 
     As such, various embodiments of the disclosure are directed to systems and methods for long-term authentication of non-fungible tokens. In various embodiments the method includes providing within the non-fungible token a hash of an identification manifest that includes one or more elements of identifying information for a unique object and a digital certificate of a trusted certifying authority. Corresponding systems comprise an associated off-chain storage for long-term storing of the unhashed identification manifest. In one or more embodiments the one or more items of identifying information include at least one element that authenticates the unique object and at least one element that authenticates the owner of the object. In one or more embodiments the system further includes a blockchain network including a distributed blockchain recording a non-fungible token located at a public address on the blockchain. In various embodiments the non-fungible token includes at least the hash of each of the one or more elements of identifying information. In certain embodiments, the non-fungible token can additionally include the unhashed identification manifest and/or the NFT certificate. In such embodiments, the non-fungible token is independently authenticatable by use of said hashes, against the one or more elements of identifying information in the off-chain storage system and/or by use of the unhashed identification manifest and/or by use of said NFT certificate against said certifying authority and/or a corresponding validating authority. In various embodiments the non-fungible token includes unhashed information including a location of said one or more elements of identifying information in the off-chain storage system. 
     The above summary is not intended to describe each illustrated embodiment or every implementation of the present disclosure. 
    
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
       The drawings included in the present application are incorporated into, and form part of, the specification. They illustrate embodiments of the present disclosure and, along with the description, serve to explain the principles of the disclosure. The drawings are only illustrative of certain embodiments and do not limit the disclosure. 
         FIG.  1    depicts a diagram of an example of a blockchain network  100  that may be accessed according to one or more embodiments of the disclosure. 
         FIG.  2    depicts a block diagram of a digital processing environment in which various embodiments can be implemented. 
         FIG.  3 A-B  depict an example off-chain storage for physical and digital objects as well as forming part of a system according to one or more embodiments of the disclosure. 
         FIG.  3 C  depicts an example blockchain including an NFT formed for such objects in accordance with one or more embodiments of the disclosure. 
         FIG.  4    depicts a schematic overview of a system for certification of authenticity of an NFT recorded in a blockchain and/or associated identifying elements stored on an off-chain storage according to one or more embodiments of the disclosure. 
         FIG.  5 A  depicts a process of minting an NFT according to one or more embodiments of the disclosure. 
         FIG.  5 B  depicts a process of minting an NFT according to further embodiments of the disclosure. 
         FIG.  6    depicts a block diagram of an example embodiment of an internal structure of a computer according to one or more embodiments of the disclosure. 
     
    
    
     While the embodiments of the disclosure are amenable to various modifications and alternative forms, specifics thereof have been shown by way of example in the drawings and will be described in detail. It should be understood, however, that the intention is not to limit the disclosure to the particular embodiments described. On the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the disclosure. 
     DETAILED DESCRIPTION 
     Referring to  FIG.  1   , a diagram of an example of a blockchain network  100  that may be accessed according to one or more embodiments of the disclosure. The blockchain network  100  is a distributed ledger peer-to-peer network and enables processing and recording of transactions without the need to trust any individual user (e.g., person, entity, program, and the like) involved in the transactions, reducing the need for intermediaries to facilitate the transaction. In various embodiments, existing applications use the blockchain network  100  to transfer and record, in the form of blockchain-based records, movement of tokens. Such blockchain-based records form a cryptographically secured backlinked list of blocks. 
     In various embodiments, the blockchain network  100  comprises multiple computing devices configured as nodes  104 . Each node  104  locally stores and maintains a respective copy  108  of the blockchain ledger in memory communicatively coupled to the node. The nodes  104  exchange messages within in the network  100  to update and synchronize the copy of the ledger  108  stored and maintained by each node  104 . In various embodiments, the nodes  104  may also execute decentralized applications (e.g., via smart contracts) for processing the messages. A message transmission  110  between nodes may be used to exchange a token in the network  100 . Depicted in  FIG.  1    the dotted lines between each set of nodes  104  indicate that similar transmissions that may be exchanged between any other set of nodes  104  in the network  100 . In various embodiments, the messages may include a confirmed transfer for recording data associated with the token being transferred, a blockchain public key for each of the one or more parties participating in the transfer. According to various embodiments the blockchain network  100  may be the Ethereum network; however, it should be understood that the network  100  could represent any suitable blockchain network. 
     Referring to  FIG.  2   , a block diagram of a digital processing environment in which various embodiments can be implemented. Client computers/devices  204  and server computers/devices  208  provide processing, storage, and input/output devices executing application programs and the like. Client computers/devices  204  are linked through communications network  212  to other computing devices, including other client computers/devices  204  and server computer(s)  208 . The network  212  can be part of a remote access network, a global network (e.g., the Internet), a worldwide collection of computers, local area or wide area networks, and gateways that may use respective protocols (e.g., TCP/IP, Bluetooth, etc.) to communicate with one another. Other electronic device/computer network architectures are suitable. For example, client computers/devices  204  may include nodes shown in  FIG.  1   , which run user applications that enable a user to communicate with an application to determine whether a user meets a work requirement. A digital wallet may be configured on the node  104  to manage one or more private keys for generating and/or signing transactions to be broadcasted on the blockchain network. 
     Server computers  208  of the computer-implemented system may be configured to include a server that executes the application. For example, the application of the server computer  208  may determine whether a user has satisfied a work requirement and produce a determination result and pair, in computer memory, an indication of the determination result with an identifier of the user or an identifier of a digital asset of the user, such as an address of a digital wallet owned by the user. The application of the server computer  208  also facilitates transfers of tokens. For another example, server computers  208  or client devices  204  may comprise peer computing devices (nodes)  104  of a distributed blockchain network of  FIG.  1   , which uses smart contracts to execute and record transactions implemented via tokens. 
     Referring to  FIG.  3 C , an example blockchain  304  is depicted including an NFT  306  formed in accordance with one or more embodiments of the disclosure.  FIG.  3 C  depicts an example NFT  306  formed in association with either a corresponding physical or digital object  307  ( 307 A or  307 B) while  FIG.  3 A-B  depict an example off-chain storage used during minting the NFT  306  for such a physical object  307 A and digital object  307 B. As described herein, the minting process and composition of the NFT  306  will be substantially similar in either instance such that the NFT and embodiments described herein are object agnostic and apply regardless of the physicality of the object. As described above, in various embodiments, the blockchain  304  is a digital ledger including one or more blocks each generally including transactions recording the transfer/generation of digital tokens to one or more public addresses. For example, like shown in  FIG.  3 C , blockchain  304  includes block  308  in which a NFT  306  is recorded as being located at public address  312 . In various embodiments, the NFT  306  is accessible via a corresponding private key of an asymmetric cryptographic key pair to the public address  312 . In such embodiments, the NFT  306  can be transferred, controlled, or otherwise managed via a digital wallet, physical wallet, or other private key management device that is configured to manage the private key for the public address  312  and sign transactions from the public address  312  for broadcast to the blockchain  304 . As such, the NFT  306  may be available for trade to one or more sellers/buyers on the network. 
     In general, in one or more embodiments, the NFT  306  comprises one or more hashed identification elements required and/or desired in the NFT for authenticating the NFT&#39;s connection with a unique object  307 . For example, and discussed further below, the NFT  306  includes hashed authenticity elements, hashed contractual elements, hashed provenance elements, and hashed additional elements. As such, the identification elements used to create the NFT  306 , including hashes to identifying information stored off-chain, the identification elements serve as a source of authentication as to the relationship of the NFT  306  with reference to a unique object  307  and as an indication of the authenticity of the NFT  306  itself. 
     In various embodiments, the NFT  306  additionally includes other information. For example, in certain embodiments, the NFT  306  can include an identification manifest  322  that includes a list  323  of all elements in the NFT. For example, in various embodiments the identification manifest  322  can include a list of the elements that are hashed in the NFT  306 . In certain embodiments, the manifest  322  could include unhashed information as well, such as unhashed versions of the hashed information. In certain embodiments the NFT  306  can include unhashed information, for example information on a storage location of unhashed versions of the hashed elements and/or location of instructions for verifying the included hashes. In one or more embodiments the manifest  322  could include a certificate  324  of a certifying authority for the off-chain storage of the unhashed versions of the hashed identifying information. In various embodiments, the certificate  324  is generated as evidence that the identifying elements included in the NFT and off-chain storage are correct and accurate. As such, in various embodiments the certificate  324  can include various information which can verify that the contents of the corresponding off-chain storage such as a list of all identifying elements  323 . 
     As a consequence of the NFT&#39;s presence on the blockchain  304 , the NFT  306  is digitally signed by the private key holder who may be the creator/owner of the object  307  and/or the creator/owner of the NFT  306  or a third party acting on behalf of the creator/owner of the object  307  and/or of the NFT  306 . A digital signature  314  that is associated with the NFT  306  is present on the blockchain  304 , for example as part of a transaction. As such, in various embodiments, the elements that are included in the NFT  306  may be referred to as digitally signed elements. Such digitally signed elements authenticate that they originate from someone in possession of the private key via their presence in the NFT  306 . For example, because the digitally signed elements are established in the minting process they therefore unambiguously indicate the source of the elements as being from one in possession of the private key. 
     In one or more embodiments the NFT  306  can include an NFT certificate  412 . In one or more embodiments the NFT certificate  412  is a digital certificate issued by a certifying authority that indicates that the NFT  306  itself has been authenticated by a certifying authority. As such, in one or more embodiments the NFT certificate  412  can be quickly used to verify the authenticity of the NFT without requiring one to validate the contents of off-chain storage. In one or more embodiments the NFT certificate  412  can further include a unique certificate serial number that can be used to identify the NFT  306 . In various embodiments, where the certification  412  is a digital certificate, the certificate can be stored within a cryptographic smart chip or other computer storage medium comprising computer program means allowing a user to view and validate cryptographic information on-board. 
     As such, in various embodiments, the NFT  306  possesses an enhanced composition at least from the elements required and/or desired in the NFT  306  which function to establish long-term authenticity of the NFT  306  including over extremely long periods of time—maintaining a clear link to a corresponding object and serving as proof of the authenticity of the NFT with respect to the object. 
     As discussed, the NFT  306  includes one or more sets of hashed and un-hashed information/data. In various embodiments, the composition of the NFT can include hashed elements/data for at least several purposes. First, hashing elements/data allows for large amounts of data to be compressed and represented within the composition of the NFT  306  regardless of the original form or content of the identifying information/elements. This allows for an arrangement where a relatively small amount of hashed data is included in the NFT itself along with some pointer or link to an off-chain location where data in its unhashed form can be found to authenticate the hash. This also benefits in avoiding adding significant amounts of material into the NFT  306 , which may or may not even be technically feasible depending on the blockchain  304 . As such, embodiments of the disclosure can be utilized on nearly any available public blockchain. In addition, because the blockchain  304  and all transactions are normally fully publically viewable on the network, hashing identifying elements allows for the inclusion of potentially sensitive or private information within the NFT  306  without compromising such information. 
     In various embodiments, the hashed elements included in the NFT will include various documents and images and other data that are digitized and hashed including hashed subject elements  370  of the subject of the NFT, hashed authenticity elements  372 , hashed provenance elements  374 , hashed contractual elements  376 , and hashed additional elements  378 . In such embodiments the hashed authenticity elements  372  include hashed information that establishes a connection between the object  307  and the NFT  306  via a collection of unhashed authenticity information stored off-chain that is designed to unambiguously point to the hashed information included in the NFT. 
     For example,  FIG.  3 A  schematically illustrates the elements of identifying information/data required and/or desired for building a NFT  306  according to the present invention for a physical object  307 A, these elements being collected and stored on an off-chain storage  321 . Like shown in the example, said elements at least part of which represent unique characteristics of the physical object  307 A may comprise subject elements  325  such as images, videos, etc.  330  representing the object  307 A, authenticity elements  326  of the object  307 A along with any unique characteristics of the object, provenance elements  327 , contractual elements  328 , and additional elements  329 . The authenticity elements  326  can include physical identifying features  340  of the object  307 A along with any unique characteristics of the object, any authentication documents  342 , such as certificates of authenticity or other documents  342  indicating analysis of the object  307 A. In certain embodiments, the authenticity elements  326  can include images, video, or audio  344  of the object  307 A. For example, recording unique physical features or designs or sounds of operation. In certain embodiments this data could additionally include frequency domain signatures  346  of the image, video, or audio data or any other type of object analysis  348  allowing authentication of the object  307 A. 
       FIG.  3 B  schematically illustrates the elements of identifying information/data required and/or desired for building a NFT  306  according to the present invention for a digital object  307 B, these elements again being collected and stored on an off-chain storage  321 . In this case, whilst the subject elements  325  may still consist in images, videos, etc.  330  representing the object  307 B, the authenticity elements  326 , instead of physical identifying features  340  of a physical object  307 A, can include source material  341  for the digital object  307 B. For example, in various embodiments the source material  341  could include the source construction resources and computer programs, original files, original images, and/or any other source material that was used in creation of the object  307 B. Of course, the authenticity elements  326  for the digital object  307 B can also include any authentication documents  342 , images, video, or audio  344  or any other type of object analysis  348  allowing authentication of the digital object  307 B. 
     For both physical objects  307 A and digital objects  307 B and such as shown in  FIGS.  3 A- 3 B , in one or more embodiments the provenance elements  327  include information that authenticate the origin of the NFT as originating from the rightful owner/creator of the object or from someone who generated the NFT on behalf of the rightful owner. In such embodiments the authenticity elements  326  include information that establishes a connection between the object  307  and the person or entity in possession of the private key. In various embodiments, the provenance elements  327  include any documents or materials providing evidence of ownership  350  and the pre-blockchain history  352  of the physical object  307 A, respectively of the digital object  307 B. For example, in various embodiments provenance elements  327  can include a deed, title documents, and historical documentation of previous sales or records that establish a chain of ownership up to the creation of the NFT  306  and/or may include, licenses, patents, appraisals  354  as well as notarized documents, joint ownership contracts, liens or other information  356 . In various embodiments, the provenance elements  327  can include evidence of the rights to create the NFT  306 . As such various embodiments allow for services where the private key can be held by a third party or generated by a third party with permission while still allowing the NFT  306  to be verified with respect to its authenticity. This feature is expected to become increasingly desirable as services and industry around NFTs and blockchain tokens develop where a private key is stored on behalf of the creator/owner of the object or the NFT is created by the third party on behalf of the creator/owner. 
     In one or more embodiments, for both physical objects  307 A and digital objects  307 B, the contractual elements  328  include information that authenticate the object and NFT against any contractual rights, legal rights, or smart contracts that are associated with the NFT  306  and/or the object  307 . In various embodiments, the contractual elements  328  include documentation of all intellectual property rights  360  associated with the object  307 . For example, in various embodiments this information may include any patents, trademarks, or copyrights associated with the object along with any contracts or licenses relating to these intellectual property rights. Such documents and information, like other parts of the elements of identifying information/data used for building the NFT  306 , thus may form part of the provenance elements  327  and/or of the contractual elements  328 , depending on the elements of information/data required or desired for the structure of the NFT  306 . In various embodiments, the contractual elements  328  can include NFT usage rights and smart contract terms  362 . For example, various embodiments include any terms for how the NFT can be used. For example, terms for display of the object or NFT, derivative works, royalties or the like. In addition, in various embodiments the smart contract code of the NFT can be hashed and included. Furthermore, the contractual elements  328  can include contractual documents like Memorandums of Understanding (MoU) or any other type of contract or agreement  364 . In various embodiments, the above-mentioned additional elements  329  can include any additional properties  368  or supplemental documentation  369  of the physical object  307 A or of the digital object  307 B. 
     Furthermore, in one or more embodiments, all elements that are supposed to be hashed have corresponding hashing instructions which are also stored next to said elements on the off-chain storage  321  and which allow for the exact reproduction of the corresponding hash values. 
     The off-chain storage  321  moreover comprises at least an identification manifest  322  that includes a complete list  323  of all elements required and/or desired in the NFT as well as, a certificate  324  of a certifying authority  414 . In various embodiments, the certificate  324  is generated as evidence that the identifying elements included in the NFT and off-chain storage are correct and accurate. As such, in various embodiments the certificate  324  can include various information which can verify that the contents of the corresponding off-chain storage such as a list of all identifying elements  323 . 
     In one or more embodiments the off-chain storage  321  can include said NFT certificate  412  which can be a signed digital or physical certificate issued for the NFT by the certifying authority  414  with a trusted root key. As described above, in one or more embodiments the NFT certificate  412  is a digital certificate issued by a certifying authority that indicates that the NFT  306  itself has been authenticated by a certifying authority. As such, in one or more embodiments the NFT certificate  412  can be quickly used to verify the authenticity of the NFT without requiring one to validate the contents of off-chain storage themselves. In one or more embodiments the NFT certificate  412  can further include a unique certificate serial number that can be used to identify the NFT  306 . In various embodiments, where the certification  412  is a digital certificate, the certificate can be stored within a cryptographic smart chip or other computer storage medium comprising computer program means allowing a user to view and validate cryptographic information on-board. 
     In various embodiments, part or all of the contents in the off-chain storage system may be stored on the off-chain storage  321  in protected manner, e.g. by encryption. For example, in certain embodiments, the contents stored on the off-chain storage system could be encrypted using the public key of a key pair held by the owner of the object  307  or of the NFT  306  or by a third party acting on behalf of said owner such that only the token holder or object owner or third party acting on their behalf may decrypt the encrypted information by use of the corresponding private key of said key pair. In general, in one or more embodiments, the owner of the object  307  or of the NFT  306  and/or a third party acting on behalf of said owner have access to the off-chain storage system in read/write mode, whereas all other parties just have no or read-only access. 
     Reverting to  FIG.  3 C , it schematically illustrates, for an object  307  which may consist in a physical object  307 A or in a digital object  307 B, the structure of a NFT  306  according to the present invention after hashing of the elements of identifying information/data stored on the off-chain storage  321  and used for minting the NFT. As far as required or desired, part or all of the elements relating to object  307  as well as collected and stored on the off-chain storage  321  such as described here above with reference to  FIGS.  3 A- 3 B , i.e. the subject elements  325 , the authenticity elements  326 , the provenance elements  327 , the contractual elements  328 , and additional elements  329 , are hashed such as to produce hashed subject elements  370 , hashed authenticity elements  372 , hashed provenance elements  374 , hashed contractual elements  376 , and hashed additional elements  378 . In various embodiments, in addition to the hashed elements the above-mentioned identification manifest  322  including the complete list  323  of all the elements comprised in the NFT and, in some embodiments, the certificate  324  of the certifying authority  414  also form the structural components of the NFT, such as shown in  FIG.  3 C . 
     While  FIG.  3 C  depicts the specific hashed elements that are described here above, this is not intended to be limiting. For example, in various embodiments hashes of any additional elements  378  can be included. Generally, the hashed information will be such that it functions to verify or authenticate the connection between the NFT  306  and the object  307  and/or the connection between the object  307  and its creator/owner and/or authenticate the NFT  306  as being rightfully minted. However, in various embodiments the hashed information could include any supplemental documentation  369  related to the object  307  and/or and its creator/owner and thus related to the NFT  306 . 
     In one or more embodiments the NFT  306  will additionally include some unhashed information. In such embodiments the unhashed information can include links  380 ,  382 ,  384 ,  386 ,  388  to locations of off-chain storage of the unhashed information/elements that is used to generate hashed elements  370 ,  372 ,  374 ,  376 ,  378 . In such embodiments, the off-chain storage  321  of the unhashed information/elements allows for an exact reproduction of the hashed values in the NFT  306 , thereby enabling the NFT  306  to be authenticated vs the set of information which details the rights, unique characteristics, and pre-chain history of the object as described above. In various embodiments, all off-chain storage is configured for permanent or long-term storage. For example, in various embodiments the unhashed information could be stored utilizing the InterPlanetary File System (IPFS), a decentralized storage solution or any long-term data storage solution. For example, in various embodiments the unhashed elements could be stored in storage locations associated with public records and certificate authorities. In certain embodiments, the unhashed elements of information/data could be stored using a blockchain network. 
     Referring to  FIG.  4   , a system  400  for producing and certifying physical authenticity documents corresponding to the NFT  306  and/or the off-chain identifying elements is schematically depicted. 
     In various embodiments, the system  400  includes a blockchain  304  including an NFT  306  that in accordance with various embodiments and as described above comprises a hash  404  of elements of identifying information/data, said hash  404  optionally being signed or provided with an NFT certificate  412  as will be described in detail here below with reference to  FIG.  5 A . In one or more embodiments the system  400  additionally includes off-chain storage  408 . In such embodiments the off-chain storage may be substantially similar to the storage systems described above with reference to  FIG.  3 A- 3 B . As such, the off-chain storage  408  is a long-term storage solution that is configured to store an unhashed copy of all elements  410  used to generate the NFT  306  which allows to authenticate the object  307 . In various embodiments, and as mentioned above, the NFT  306  and/or off-chain storage  408  can include an NFT certificate  412  which in various embodiments can be a signed digital or physical certificate issued from a certifying authority  414  with a trusted root key. In one or more embodiments, the system  400  may additionally include a public key infrastructure (PKI)  418  comprising a certifying authority  414  and a validating authority  416 . 
     As described above, in various embodiments, the NFT certificate  412  is a certificate from a trusted authority  414  that is generated as evidence that the NFT  306  has been authenticated by a certifying authority and may for example consist in a X.509 or equivalent certificate. As such, in one or more embodiments the NFT certificate  412  can be quickly used to verify the authenticity of the NFT without requiring one to validate the contents of off-chain storage themselves. In one or more embodiments the NFT certificate  412  can further include a unique certificate serial number that can be used to identify the NFT  306 . In various embodiments, where the certification  412  is a digital certificate, the certificate can be stored within a cryptographic smart chip or other computer storage medium comprising computer program means allowing a user to view and validate cryptographic information on-board. 
     In various embodiments, once the NFT certificate  412  has been generated, the validity of the digital certificate and therefore authenticity of the corresponding NFT  306  may be checked by the owner of the NFT, or further audited by a third-party validating authority  416  whenever and wherever required, by use of network computing means, including computers connected to a network. To this effect, the network computing means cooperates with the storage means and the validating authority  416  and/or the certifying authority  414  so as to sensibly output, in real time, the status of validity of the NFT certificate  412 . 
     For example, in various embodiments the validating authority  416  or owner of the NFT checks the validity period of the certificate as well as whether it has been revoked, the latter against the certifying authority  414  using, e.g., a certificate revocation list (CRL) generally hosted at the certifying authority or an online certificate status protocol (OCSP). Both of these are a kind of list comprising information on issued certificates, in particular a corresponding entry in case individual certificates were compromised. Thus, this comprises interaction of the network computing means with both the storage means and the validating and/or the certifying authority such as to allow access by the validating and/or certifying authority to the NFT certificate. This demonstrates that embodiments provide for a convenient technical solution to the problem of providing a non-forgeable NFT certificate of authenticity which may easily, whenever as well as almost wherever, be audited for its validity. 
     Further, if so desired, the system  400  allows to establish long-term and persistent links between the NFT  306  and a “Back-to-Physical” object  402 , respectively long-term and persistent links between the object  307  which is linked to the NFT  306  and a “Back-to-Physical” object  402 . In one or more embodiments, the Back-to-Physical object  402  is a device or object including some computer readable storage medium where various data related to the NFT  306  can be stored such that the storage medium becomes a physical manifestation of the NFT  306 . For example, in various embodiments a copy of the NFT  306 , a copy of one or more transactions of the NFT  306 , links to the NFT in a block explorer, a hash of the NFT  306 , the NFT certificate  412  or other information could be stored within the storage medium. Furthermore, in one or more embodiments, once this is established, an additional NFT optionally can be minted for the storage medium in order to authenticate the link between the original NFT  306  and the storage medium. Minting the additional NFT may be performed in the same manner as minting the original NFT  306 , such as will be described in detail here below with reference to  FIG.  5 A . In such embodiments, the new NFT can then be traded on a blockchain  422 . In one or more embodiments this additional NFT is referred to as a “Back-to-Physical” NFT  424 , whereby the Back-to-Physical NFT is a digital representation of that processes described herein has been successfully performed. In various embodiments, a physical embodiment of the “Back-to-Physical” NFT  424  can be established using NFC tags  426  as a storage medium. In various embodiments, the structure and composition of the original NFT  306  along with identifying information for the NFT  306  is stored in the NFC tag  426 . In various embodiments, the NFC tag  426  could be connected to or attached or included with the object  402  corresponding to the NFT  306 . 
     However, in certain embodiments the NFC tag  426  could be connected to or attached or included with another object. For example, in some embodiments the NFC tag  426  could be included with or attached to a Back-to-Physical object  402  which is a copy of the object  307  which is linked to the original NFT  306 . In general, the Back-to-Physical object  402  may in this case be a manufactured or printed physical manifestation of the original object  307  and may for example consist in a print of a digital image or animation of the original object  307 , in a holographic projection of the object  307 , in a miniature model of the object  307 , in a physical certificate representing ownership of the object  307  or of the original NFT  306 , or any other such physical representation of the original object  307 . 
     In some embodiments the NFC tags  426  can be programmed using a PKI (public key infrastructure) certificate, or other digital signature technology known in the art. In various embodiments, the Back-to-Physical NFT  424  and/or physical embodiment can further receive certification using a certifying authority  414  as described herein. In such embodiments, the inclusion of identifying information of the NFT  306  within the physical embodiment of the Back-to-Physical object  402  renders a public-private key pair programmed into an NFC tag  426  with information included such that the physical embodiment is authenticatable on the blockchain. In such embodiments the NFC tag  426  could function as a physical certificate to represent ownership of the Back-to-Physical NFT  424  and thus of the Back-to-Physical object  402 . In various embodiments the NFC tag could contain a private key of a public-private key pair corresponding to the Back-to-Physical NFT  424 . In such embodiments, possession of the NFC tag  426 , respectively of the Back-to-Physical object  402  to which the NFC tag  426  is attached to, would thus demonstrate possession of the associated Back-to-Physical NFT  424 . 
     Referring to  FIG.  5 A , a method  500  of minting a long-term persistently authenticatable NFT is depicted according to one or more embodiments of the disclosure. In one or more embodiments the method  500  includes, at operation  502 , preparing elements of identifying information/data required and/or desired for creating a NFT  306  according to the present invention for an object  307  which may consist in a physical object  307 A or a digital object  307 B. As described above, these elements can include subject elements  325 , authenticity elements  326 , contractual elements  327 , provenance elements  328 , and additional elements  329  which independently serve to prove the object&#39;s authenticity and origin and to prove/show ownership or rights to mint an NFT. In one or more embodiments the method  500  includes, at operations  504  and  506 , digitizing the identifying elements and storing the unhashed elements in permanent off-chain storage  321 . In various embodiments, hashing instructions for each of these elements  325 ,  326 ,  327 ,  328 ,  329  are provided and stored together with the corresponding element in the off-chain storage  321 . 
     In one or more embodiments, the method  500  further includes, at operation  508 , preparing an identification manifest  322  that comprises a complete list  323  of all elements required and/or desired in the NFT  306 , such as previously stored in the off-chain storage  321 , the identification manifest  322  then being stored in the off-chain storage  321 . In some embodiments, the method  500  includes, at operation  508 , adding to or listing in the identification manifest  322  the certificate  324  of the trusted certifying authority  414  and storing the certificate  324  in the identification manifest  322  in the off-chain storage  321  as well. The method  500  further includes, at operation  510 , hashing all of or each of the required/desired and digitized identifying elements  325 ,  326 ,  327 ,  328 ,  329  as well as attaching the identification manifest  322  as well as said hash or hashes  370 ,  372 ,  374 ,  376 ,  378  of these elements to the NFT  306 . In some preferred embodiments, the method  500  includes, at operation  512 , providing for each of the required and/or desired identifying elements  325 ,  326 ,  327 ,  328 ,  329 , respectively for the corresponding hashes  370 ,  372 ,  374 ,  376 ,  378  of these elements created in previous operation  510 , links  380 ,  382 ,  384 ,  386 ,  388  to locations in the off-chain storage  321  of the unhashed information/elements that is used to generate hashed elements  370 ,  372 ,  374 ,  376 ,  378  as well as attaching to the NFT  306  these links  380 ,  382 ,  384 ,  386 ,  388  to locations in the off-chain storage  321 . 
     In various embodiments, the method  500  includes, at operation  514 , preparing a NFT certificate  412  to be issued by said certifying authority  414  for the NFT  306 . In various embodiments, the NFT certificate  412  can be a certificate corresponding to the contents of the off-chain storage and/or identification manifest and/or the hash of part or all of the elements of identifying information on the off-chain storage  321 . A certificate definition prepared for issuing the NFT certificate  412  may include a hash of the entire group of required/desired identifying elements and of said identification manifest  322  as well as, optionally, the unhashed elements. Alternatively, in other embodiments, the certificate definition prepared for issuing the NFT certificate  412  may include the hashes of the individual elements of the NFT. Put another way, at operation  514 , in various embodiments a digital certificate to be issued may comprise any or all of the identifying information that is used to construct the NFT  306 . 
     At operation  516 , the method  500  includes issuing and signing the NFT certificate  412  by said certifying authority  414 , which can include generating a unique certificate serial number allowing its use for identifying the NFT  306 . In this case, the private key of the asymmetric cryptographic key pair of the certifying authority  414  is used to create a digital signature provided by the certifying authority  414  for the NFT certificate  412 , such that the public key of this key pair may be used to verify authenticity of the NFT  306 . As such, in various embodiments the NFT certificate  412  can be used to independently verify any of the identifying information by relying on the certifying authority  414 . In certain embodiments, the signed certificate may be provided, like described above, directly by use of the public-private key pair of the certifying authority  414  or, alternatively, indirectly by use of a key pair generated by a third party whose authenticity and integrity may be verified by the certifying authority. In certain simplified embodiments not illustrated in  FIG.  5 A , the hash of part or all of the elements of identifying information on the off-chain storage  321 , instead of being certified by a certificate signed directly by a certifying authority (CA) which next to a validating authority (VA) forms part of a public key infrastructure (PKI) or signed indirectly by a third party authenticated by said certifying authority, may be just signed by use of the asymmetric cryptographic public-private key pair of the certifying authority or by use of a key pair generated by a third party whose authenticity and integrity may be verified by the certifying authority. For example, the hash may be signed with the help of a key-dependent hash function, by use of the private key of the corresponding key pair. The signature of the hash provided in this manner may then be verified by use of the public key of the corresponding key pair. In certain simplified embodiments not illustrated in  FIG.  5 A , either, the hash of part or all of the elements of identifying information on the off-chain storage  321  may be neither certified by a certificate signed directly by a certifying authority or signed indirectly by a third party authenticated by said certifying authority nor signed by use of the asymmetric cryptographic public-private key pair of the certifying authority or of a key pair generated by a third party, but the hash may simply, as such, form part of the NFT  306 . In the latter case, the NFT  306  on the blockchain  304  and the elements of identifying information on the off-chain storage  321  are connected by an unsigned/uncertified hash  404 , which nevertheless allows to verify authenticity of the NFT  306  by checking the hash value by use of the elements of identifying information on the off-chain storage  321  which are accessible via the links  380 ,  382 ,  384 ,  386 ,  388  attached to the NFT  306 . In this case, instead of generating a unique certificate serial number, operation  516  of the method  500  can include generating a unique NFT serial number allowing its use for identifying the NFT  306 . In the former two cases, the NFT  306  on the blockchain  304  and the elements of identifying information on the off-chain storage  321  are connected by a signed, respectively by a certified hash  404 , such that authenticity of the NFT  306  may be checked directly by verifying the corresponding signature of hash  404 , respectively by verifying the NFT certificate  412 , it being nevertheless possible also in these cases to verify authenticity of the NFT  306  by checking the hash value by use of the elements of identifying information on the off-chain storage  321 . 
     The method  500  includes, at operation  518 , minting an NFT that includes, in various embodiments, one or more of hashes  370 ,  372 ,  374 ,  376 ,  378  of the elements  325 ,  326 ,  327 ,  328 ,  329  or a hash of the entire group of these elements, links  380 ,  382 ,  384 ,  386 ,  388  to locations in the off-chain storage  321  of these elements, the identification manifest  322  comprising a complete list  323  of these elements and the certificate  324  of the trusted certifying authority  414 , as well as the NFT certificate  412  which comprises a hash of the required/desired identifying elements and, if so desired, of said identification manifest  322  and which is signed as described above by the certifying authority  414  or by a third party authenticated by said certifying authority  414 . In the simplified embodiments mentioned above and not illustrated in  FIG.  5 A , the method  500  includes, at operation  518 , minting an NFT that includes an unsigned or signed hash of the desired/required elements of identifying information  325 ,  326 ,  327 ,  328 ,  329  and, optionally, links  380 ,  382 ,  384 ,  386 ,  388  to locations in the off-chain storage  321  of these elements, as well as, optionally, the identification manifest  322  comprising a complete list  323  of these elements and/or the certificate  324  of the trusted certifying authority  414 , as far as the hash is signed by the certifying authority. In the most simple embodiments not illustrated in  FIG.  5 A , the minted NFT  306  includes an unsigned or signed or certified hash of the desired/required elements of identifying information  325 ,  326 ,  327 ,  328 ,  329 , which in all these cases is preferably completed by links  380 ,  382 ,  384 ,  386 ,  388  to locations in the off-chain storage  321  of these elements. 
     In various embodiments, minting an NFT at operation  518  of the method  500  includes providing a digital signature by the creator/owner of the object  307  and/or the creator/owner of the NFT  306  or by a third party acting on behalf of said creator/owner. Said digital signature is provided by use of an asymmetric cryptographic key pair comprising a public key and a private key held by said creator/owner or by said third party, the private key of this creator&#39;s/owner&#39;s or third party&#39;s key pair being used to create the digital signature which is included on the blockchain  304 , whilst the public key may be used to verify the digital signature, such that the actual identity of the NFT minter, in principle, may be verified. However, in conventional blockchain schemes it is usual or at least possible that the NFT minter is pseudo-anonymous due to the fact that his private key corresponds to a web-of-trust-like key pair, thus leading to pseudo-anonymity of the NFT minter, respectively of the creator/owner of the object  307  and/or of the creator/owner of the NFT  306 . In various embodiments of the method  500  according to the present invention, wherein the system  400  comprises a PKI and therefore comprises a certifying authority (CA) as well as a validating authority (VA), minting an NFT at operation  518  comprises a “hierarchical-type” key pair connected to said certifying authority and being generated by said creator/owner of the object  307  or the creator/owner of the NFT  306  or by a third party acting on their behalf, such that their authenticity and integrity and/or their identity may be verified by the certifying authority and the corresponding validating authority. Therefore, although the above mentioned key pair used for the digital signature provided by the certifying authority  414 , or by a third party authenticated by the certifying authority  414 , for the NFT certificate  412  in principle may be used to verify authenticity and integrity of the NFT  306  against the certifying authority  414  and/or the validating authority  416 , various embodiments of a method  500  according to the present invention additionally provide, directly within the minted NFT  306 , further means to verify authenticity and integrity of the NFT  306  as well as of the corresponding object  307  and/or of its creator/owner, namely the public key of the above mentioned creator&#39;s/owner&#39;s or third party&#39;s key pair being used to create the digital signature of the NFT  306  and/or the public key of the above mentioned certificate  324  of the trusted certifying authority  414  in the identification manifest  322  of the NFT  306 . In particular, in one or more embodiments, the certifying authority  414  may not only act by issuing and signing said NFT certificate  412  or by signing said hash  404  in order to certify authenticity and integrity of the elements  325 ,  326 ,  327 ,  328 ,  329  required or desired in the NFT  306 , but may also act in order to allow for verification of the authenticity and integrity and/or of the identity of the creator/owner of the object  307  and/or of the creator/owner of the NFT  306  and/or of any third party acting on their behalf. 
     Like mentioned above, in one or more embodiments of a method  500  of minting a long-term persistently authenticatable NFT according to the disclosure, several of the above mentioned operations are optional and  FIG.  5 B  illustrates an example of such a method. 
     Referring to  FIG.  6   , a block diagram of an example embodiment of an internal structure of a computer/computing node  204 ,  208  in the digital processing environment of  FIG.  2    is depicted. In various embodiments, the computer  204 ,  208  may be used to facilitate displaying audio, image, video or data signal information. As such, in various embodiments the computer  204 ,  208  may include a processor  604 , memory  606  and a system bus  608 , that connects different elements of the computer  204 ,  208  and enables the transfer of data between the elements. In various embodiments, memory  606  includes various computer implemented storage mediums such as RAM, cache memory, and other system storage. In various embodiments, computer executable code can be included or stored within memory  606  for execution by the processor  604 . In various embodiments, the computer  204 ,  208  additionally includes an I/O device interface  610  for connecting various input  612  and output devices  614  (e.g., keyboard, mouse, touch screen interface, displays, printers, speakers, audio inputs and outputs, video inputs and outputs, microphone jacks, etc.) to the computer. In various embodiments, a network interface  616  allows the computer to connect to various other devices attached to a network, such as the network  212  of  FIG.  2   , disclosed above. 
     Software components of the computer-implemented system may be configured using any known programming language, including any high-level, object-oriented programming language. The computer-implemented system may include instances of processes that enable execution of transactions and recordation of transactions. 
     Further example embodiments disclosed herein may be configured using a computer program product; for example, controls may be programmed in software for implementing example embodiments. Further example embodiments may include computer program means stored in a computer-readable medium adapted to implement a method according to the present invention and, in particular, a non-transitory computer-readable medium containing instructions that may be executed by a processor which, when loaded and executed, cause the processor to complete methods described herein. It should be understood that elements of the block and flow diagrams may be implemented in software or hardware, such as via one or more arrangements of circuitry of  FIG.  5   , disclosed above, or equivalents thereof, firmware, a combination thereof, or other similar implementation determined in the future. In addition, the elements of the block and flow diagrams described herein may be combined or divided in any manner in software, hardware, or firmware. If implemented in software, the software may be written in any language that can support the example embodiments disclosed herein. The software may be stored in any form of computer-readable medium, such as random-access memory (RAM), read only memory (ROM), compact disk read-only memory (CD-ROM), and so forth. In operation, a general purpose or application-specific processor or processing core loads and executes software in a manner well understood in the art. It should be understood further that the block and flow diagrams may include more or fewer elements, be arranged or oriented differently, or be represented differently. It should be understood that implementation may dictate the block, flow, and/or network diagrams and the number of block and flow diagrams illustrating the execution of embodiments disclosed herein. 
     One or more embodiments may be a computer program product. The computer program product may include a computer-readable storage medium (or media) including computer-readable program instructions for causing a processor to perform one or more processes or functions as described herein. The computer-readable storage medium is a tangible device that can retain and store instructions for use by an instruction execution device. The computer-readable storage medium may be, for example, an electronic storage device, a magnetic storage device, an optical storage device, or other suitable storage media. 
     A computer-readable storage medium, as used herein, is not to be construed as being transitory signals per se, such as radio waves or other freely propagating electromagnetic waves, electromagnetic waves propagating through a waveguide or other transmission media (e.g., light pulses passing through a fiber-optic cable), or electrical signals transmitted through a wire. 
     Program instructions, as described herein, can be downloaded to respective computing/processing devices from a computer-readable storage medium or to an external computer or external storage device via a network, for example, the Internet, a local area network, a wide area network and/or a wireless network. A network adapter card or network interface in each computing/processing device may receive computer-readable program instructions from the network and forward the computer-readable program instructions for storage in a computer-readable storage medium within the respective computing/processing device. 
     Computer-readable program instructions for carrying out one or more embodiments, as described herein, may be assembler instructions, instruction-set-architecture (ISA) instructions, machine instructions, machine-dependent instructions, microcode, firmware instructions, state-setting data, or either source code or object code written in any combination of one or more programming languages, including an object-oriented programming language such as Smalltalk, C++ or the like, and conventional procedural programming languages, such as the “C” programming language or similar programming languages. 
     The computer-readable program instructions may execute entirely on a single computer, or partly on the single computer and partly on a remote computer. In some embodiments, the computer-readable program instructions may execute entirely on the remote computer. In the latter scenario, the remote computer may be connected to the single computer through any type of network, including a local area network (LAN) or a wide area network (WAN), or public network. 
     One or more embodiments are described herein with reference to flowchart illustrations and/or block diagrams of methods, systems, and computer program products for enhancing target intercept according to one or more of the embodiments described herein. It will be understood that each block of the flowchart illustrations and/or block diagrams, and combinations of blocks in the flowchart illustrations and/or block diagrams, may be implemented by computer-readable program instructions. 
     These computer-readable program instructions may be provided to a processor of a general purpose computer, special purpose computer, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions/acts specified in the flowchart and/or block diagram block or blocks. These computer-readable program instructions may also be stored in a computer-readable storage medium that can direct a computer, a programmable data processing apparatus, and/or other devices to function in a particular manner, such that the computer-readable storage medium having instructions stored therein comprises an article of manufacture including instructions which implement aspects of the function/act specified in the flowchart and/or block diagram block or blocks. 
     The computer-readable program instructions may also be loaded onto a computer, other programmable data processing apparatus, or other device to cause a series of operational steps to be performed on the computer, other programmable apparatus or other device to produce a computer-implemented process, such that the instructions which execute on the computer, other programmable apparatus, or other device implement the functions/acts specified in the flowchart and/or block diagram block or blocks. 
     The flowchart and block diagrams in the figures illustrate the architecture, functionality, and operation of possible implementations of systems, methods, and computer program products according to various embodiments of the present invention. In this regard, each block in the flowchart or block diagrams may represent a module, segment, or portion of instructions, which comprises one or more executable instructions for implementing the specified logical function(s). In some embodiments, the functions noted in the block may occur out of the order noted in the figures. For example, two blocks shown in succession may, in fact, be executed substantially concurrently, or the blocks may sometimes be executed in the reverse order, depending upon the functionality involved. 
     It should be understood that the term “blockchain” as used herein includes all forms of electronic, computer-based, distributed ledgers. These include consensus-based blockchain and transaction-chain technologies, permissioned and un-permissioned ledgers, shared ledgers and variations thereof. While Bitcoin and Ethereum may be referred to herein for the purpose of convenience and illustration, it should be noted that the disclosure is not limited to use with the Bitcoin or Ethereum blockchains and alternative blockchain implementations and protocols fall within the scope of the present disclosure. 
     It should also be understood that, while the systems and processes described above have been applied to non-fungible tokens, various embodiments of these systems and methods also have applicability in the context of a variety of other blockchain applications. For example, various embodiments have applicability for persistent authentication of tokens such as Security Token Offerings (STO) and Global Token Exchanges (GTE), as well as for any other applications involving similar or substantially equivalent types of tokens and blockchains. 
     The descriptions of the various embodiments of the present disclosure have been presented for purposes of illustration, but are not intended to be exhaustive or limited to the embodiments disclosed. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the described embodiments. The terminology used herein was chosen to explain the principles of the embodiments, the practical application or technical improvement over technologies found in the marketplace, or to enable others of ordinary skill in the art to understand the embodiments disclosed herein. 
     In light of the above description, it is clear to a person skilled in the art that systems and methods according to the present invention provide numerous advantages and allow for long-term authentication of non-fungible tokens, in particular by means of a NFT certificate signed by a certifying authority, by a hash signed by a certifying authority, or by a simple hash, included in the non-fungible token as well as by means of identifying elements being used to create the non-fungible token and stored in persistent manner in an off-chain storage system.