Abstract:
In one embodiment of the present invention, a source point of a supply chain secures shipment of an object by devising an encryption key and encrypting a message using the encryption key to produce an encrypted message. A portion or portions of the encryption key and the encrypted message are included or incorporated within the object to be shipped, packaging surrounding the object, and/or labels affixed to the object or packaging, prior to shipping the object to a destination point within the supply chain. Upon receipt of the object from the supply chain, the destination point can extract the portion or portions of the encryption key and the encrypted message from the object, packaging surrounding the object, and/or labels affixed to the object or packaging, obtain the remaining portion of the encryption key directly from the source point, reassemble the encryption key, and decrypt the encrypted message to produce a computed message. The destination point can then obtain the original message from the source point and compare the original message to the decrypted message in order to determine whether or not the shipment is authentic.

Description:
TECHNICAL FIELD 
     The present invention is related to security and authentication, and, in particular, to the authentication of physical objects shipped through supply chains. 
     BACKGROUND OF THE INVENTION 
     Security of shipped objects in supply chains has been a problem for manufacturers, shippers, distributors, and recipients of shipped goods for thousands of years. Security issues have been addressed by many different techniques, including various types of seals, such as wax seals, markings and encodings, trusted distributors and distribution agencies, trademarks, armed guards, and, more recently, mechanical and electronic devices and computer-based systems for ensuring that an object sent from a source point in a supply chain reaches a destination point intact, untampered with, undamaged, and in a timely fashion. However, as methods for securing shipment of objects have evolved, methods used by counterfeiters and thieves to defeat security methods have also evolved. As a result, theft, counterfeiting, shipment delays, and shipment-routing problems continue to plague supply chains. 
     One important example of supply-chain-security problems in contemporary commerce is the shipment of pharmaceuticals from pharmaceutical manufacturers to various distributors and retail outlets.  FIGS. 1 and 2  illustrate a pharmaceutical-supply-chain context used, in subsequent subsections, as one context for application of the methods of the present invention. In  FIG. 1 , a large pharmaceutical manufacturer  102  manufacturers pharmaceuticals that are shipped, in the case of  FIG. 1 , by rail  104  to a number of centralized distribution facilities, such as centralized distribution facility  106 . From these centralized distribution centers, smaller shipments  108  of pharmaceuticals are made to a number of regional distribution centers, including regional distribution center  110  in  FIG. 1 , from which the pharmaceuticals are then shipped by local transport  112  to a number of local distribution centers, including local distribution center  114  in  FIG. 1 . The pharmaceuticals are finally distributed, by local transport  116 , to a number of retail outlets, such as the drugstore  118  shown in  FIG. 1 . As shown in  FIG. 2 , the pharmaceuticals may be initially shipped in bulk  202  from the pharmaceutical manufacturer to centralized distribution facilities. The pharmaceuticals may be packaged into bottles at the centralized distribution facilities, and shipped in large packages  204  to regional distribution centers. In the regional distribution centers, the containers may be repackaged  206  into smaller-volume packages, in which the pharmaceuticals are distributed through the supply chain to local distribution centers, from which either small packages or individual bottles  208  of the pharmaceuticals may be distributed to retail outlets. At the retail outlet, pharmaceuticals may again be repackaged into familiar prescription bottles for individual consumers. 
     The pharmaceutical supply chain illustrated in  FIGS. 1 and 2  is but one example of a myriad possible organizations of pharmaceutical supply chains. In some cases, the pharmaceuticals may be fully packaged by the manufacturer in the packaging in which the pharmaceuticals are intended to be delivered to retail outlets. In other cases, bulk powdered or liquid pharmaceuticals may be shipped by manufacturers to secondary drug manufacturers, where they are formed into pills, gelatin capsules, glass bottles with rubber septa for loading syringes, and other final drug products, and then distributed to the supply chain. Retail outlets are but one example of a destination point in a supply chain. In the pharmaceutical-supply-chain context, for example, other destination points include clinics, hospitals, government agencies, and other health care establishments. 
     Drug counterfeiting has become an increasingly common and increasingly dangerous problem for pharmaceutical manufacturers, distributors, retail outlets, health-care facilities, and consumers. Drug counterfeiters seek to insert falsely labeled, counterfeit pharmaceuticals into the supply chain at various intermediate points in the supply chain in between the manufacturer, or other trusted source point, and a destination point, such as a retail outlet. By doing so, the counterfeiters can circumvent patent rights, government oversight and quality standards, and other well-designed and protective barriers to entering the pharmaceuticals marketplace. However, counterfeit drugs may be either ineffective or dangerous. Therefore, manufacturers, distributors, retailers, and consumers of pharmaceuticals have all recognized the need for improved security techniques for ensuring that the pharmaceuticals received by retail outlets, consumers, and health-care facilities are the legitimate products shipped from trusted source points in the pharmaceutical supply chain, including manufacturers, secondary drug manufacturers, centralized distributors, and other trusted points in the pharmaceutical supply chain. 
     SUMMARY OF THE INVENTION 
     In one embodiment of the present invention, a source point of a supply chain secures shipment of an object by devising an encryption key and encrypting a message using the encryption key to produce an encrypted message. A portion or portions of the encryption key and the encrypted message are included or incorporated within the object to be shipped, packaging surrounding the object, and/or labels affixed to the object or packaging, prior to shipping the object to a destination point within the supply chain. Upon receipt of the object from the supply chain, the destination point can extract the portion or portions of the encryption key and the encrypted message from the object, packaging surrounding the object, and/or labels affixed to the object or packaging, obtain the remaining portion of the encryption key directly from the source point, reassemble the encryption key, and decrypt the encrypted message to produce a computed message. The destination point can then obtain the original message from the source point and compare the original message to the decrypted message in order to determine whether or not the shipment is authentic. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIGS. 1 and 2  illustrate a pharmaceutical-supply-chain context used, in subsequent subsections, as one context for application of the methods of the present invention. 
         FIG. 3  illustrates a basic principle underlying cryptographic methodologies. 
         FIG. 4  illustrates an exemplary technique for encoding a 16-bit binary integer within a label. 
         FIG. 5A  shows one possible printing of the label, discussed above with reference to  FIG. 4 . 
         FIG. 5B  shows an alternative printing of the label, discussed above with reference to  FIG. 4 . 
         FIG. 6  illustrates a first embodiment of the present invention. 
         FIG. 7  shows an alternative embodiment of the present invention, similar to the first embodiment illustrated in  FIG. 6 . 
         FIG. 8  is a control-flow diagram representing steps undertaken by a source point, or manufacturer, in order to secure a shipment according to one embodiment of the present invention. 
         FIG. 9  is a control-flow diagram representing steps undertaken by a shipment recipient in order to authenticate a shipment according to one embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The present invention is related to securing shipment of objects through supply chains. In described embodiments of the present invention, an encryption-based system is employed to allow the recipient of a shipment to authenticate the shipment based on information included or incorporated within the object shipped, or incorporated within or affixed to various, nested levels of packaging surrounding the object. First, basic cryptography is reviewed in the following subsection. Then, in a subsequent subsection, embodiments of the present invention are discussed. 
     Review of Basic Cryptography 
     Certain embodiments of the present invention employ cryptographic methodologies in order to secure shipment of objects through supply chains. In this subsection, an overview of a number of basic cryptographic methods is provided.  FIG. 3  illustrates a basic principle underlying cryptographic methodologies. Cryptography is designed to transform plain text information into encoded information that cannot be easily decoded by unauthorized entities. For example,  FIG. 3  shows a plain text message  302  that includes an English-language sentence. This plain text message can be encrypted by any of various encryption functions E  304  into a corresponding cipher text message  306  that is not readily interpretable. An authorized user is provided with a decryption function D  308  that allows the authorized user to decrypt the cipher text message  306  back to the plain text message  310 . 
     The basic cryptographic methods can be described using the following definitions: 
               A   m     =       alphabet   ⁢           ⁢   for   ⁢           ⁢   messages     =     {       a     m   1       ,     a     m   2       ,       a     m   3       ⁢           ⁢   …   ⁢           ⁢     a     m   n           }                     A   c     =         alphabet   ⁢           ⁢   for   ⁢           ⁢   cipher     -   text     =     {       a     c   1       ,     a     c   2       ,       a     c   3       ⁢           ⁢   …   ⁢           ⁢     a     c   n           }                   M   =       message   -   space     =       strings   ⁢           ⁢   of   ⁢           ⁢     a   m     ⁢     
     ⁢   C     =       cipher   -     text   ⁢           ⁢   space       =     strings   ⁢           ⁢   of   ⁢           ⁢     a   c     ⁢     
     ⁢           K   =       key   ⁢           ⁢   space     =         {       e   1     ,       e   2     ⁢           ⁢   …   ⁢           ⁢     e   n         }     ⁢           ⁢   where   ⁢           ⁢       E     e   i       ⁡     (   m   )         →   c                   =         {       d   1     ,       d   2     ⁢           ⁢   …   ⁢           ⁢     d   n         }     ⁢           ⁢   where   ⁢           ⁢       D     d   i       ⁡     (   d   )         →   m                           
Plain text messages are instances of messages contained within the message space M and cipher text messages are instances of the cipher text messages contained within cipher-text space C. A plain text message comprises a string of one or more characters selected from a message alphabet A m , while a cipher-text message comprises a string of one or more characters selected from the cipher-text alphabet A c . Each encryption function E employs a key e and each decryption function D employ a key d, where the keys e and d are selected from a key space K.
 
     A key pair is defined as follows:
 
key pair=( e,d )
 
where eεK, dεK, D d  (E e (m))=m, and mεM.
 
     One key of the key pair, e, is used during encryption to encrypt a message to cipher text via an encryption function E, and the other key of the key pair, d, can be used to regenerate the plain text message from the cipher-text message via a decryption function D. In symmetric key encryption, e and d are identical. In asymmetric, public-key cryptographic methods, key pairs (e,d) have the property that, for all key pairs (e,d), no function ƒ(e)=d can be easily determined. Thus, the encryption key e of a public-key pair (e,d) can be freely distributed, because the corresponding decryption key d of the public-key pair cannot be determined from the encryption key e. 
     DESCRIBED EMBODIMENTS OF THE PRESENT INVENTION 
     Information may be encoded graphically into labels and other graphical objects and representations.  FIG. 4  illustrates an exemplary technique for encoding a 16-bit binary integer within a label. The label  402  is a rectangular piece of paper, polymer, or other planar material on which label information is printed. In the exemplary label of  FIG. 4 , five text fields  401 - 405  are printed, along with optional printing of between zero and three dots, or filled disks,  406 - 408 . The 16-bit integer is encoded by choosing 16 different features of the label, and providing two different choices for the features. For example, the first bit b 0  of the 16-bit integer encodes whether or not the bottom-left text field  404  is printed at a first height  410  or a second height  412 . When printed at the first height  410 , bit b 0  of the 16-bit integer has the value “1,” and when printed at the second height  412 , bit b 0  has the value “0.” The second bit, b 1 , of the 16-bit integer indicates whether or not the upper left dot, or filled disk,  406  is printed on the label. Similarly, each of the remaining 14 bits of the 16-bit integer are determined by the heights, horizontal offsets of the five text fields, presence or absence of dots  407  and  408 , and the font size of the textual information printed in text fields  402 - 405 , as indicated in  FIG. 4 . 
       FIG. 5A  shows one possible printing of the label, discussed above with reference to  FIG. 4 . The label  502  is shown in  FIG. 5A  along with the corresponding 16-bit integer  504  that can be extracted from the label by noting which of the two variants for each of the features shown in  FIG. 4  are used in the label. For example, the upper, left-hand dot  406  is printed on label  502 . Therefore, bit b 1   506  of the 16-bit integer  504  has the value “0,” as shown in  FIG. 4 , indicating that the dot is printed. Similarly, the presence of the upper, right-hand dot  407  on the label is reflected in the value “1” for bit b 5   508  in the 16-bit integer  504 , again as indicated by the encoding scheme outlined in  FIG. 4 . The fact that a large font size was used to print the word “aspirin” in text field  402  is reflected by the value “1” for bit b 8   510  of the 16-bit word  504 . The values of each of the other bits of the 16-bit integer  504  similarly reflected in the printing-feature variants used to print the label  502 .  FIG. 5B  shows an alternative printing of the label, discussed above with reference to  FIG. 4 .  FIG. 5B  shows an alternative printing of the label, with a different corresponding 16-bit integer reflecting the printing-feature variants used in the alternative printing. Although the features chosen for the current example are rather easily detected by visual inspection, far more subtle features can be used to encode information in a label for extraction by automated methods. Commonly used labels provide a plethora of printing features, the variants for which can be used to encode arbitrarily sized binary integers, or other numeric or textual information. 
     In one embodiment of the present invention, a symmetric encryption key and encryption scheme is used, along with encoding of information in labels, as discussed above with reference to FIGS.  4  and  5 A-B, in order to secure shipment of an object through a supply chain. It should be appreciated that a label may be a piece of printed paper, plastic, film, or composite material affixed to a package or object, but may also be information directly incorporated within, or embossed or imprinted on, an object being shipped or packaging enclosing the object.  FIG. 6  illustrates a first embodiment of the present invention. The source point in the supply chain prepares an object for shipment  602 . The source point then determines, perhaps by a random or pseudorandom method, a particular symmetrical encryption key e  604 . The source point encodes one portion  606  of the symmetrical encryption key into a printed label  608  that is affixed to the shipment  602 . The source point also devises a message  610  M and uses the encryption key e to encrypt the message to an encrypted form C  612 . The encrypted message C is also placed onto the label  614 , either in a directly readable form, or using the encoding method discussed above with reference to FIGS.  4  and  5 A-B. The object  602  is then shipped  616  to the destination point, generally through a series of intermediate points, such as distributors. At the destination point, the portion  606  of the encryption key e encoded in the label  608  is extracted and combined with the remainder of the encryption key e  615  directly transmitted to, or revealed to, the destination point by the source point. This allows the destination point to reassemble the entire, intact encryption key e  604 . The destination point also extracts the encrypted message C  612  from the label  608 , and uses the reconstructed encryption key e to decrypt  618  the encrypted message to produce a computed version of the original message, M C    620 . The destination point receives, directly from the source point, a copy  622  of the plain-text message M, labeled M R  in  FIG. 6 , and compares  624  the computed version of the original message, M C , to the directly received copy M R  of the plain-text message. If M R  is equal to M C , then the shipment is deemed authenticated  626 , and is otherwise deemed invalid, or not authenticated  628 . Note that the source point, in the pharmaceutical-supply-chain context discussed above with reference to  FIGS. 1 and 2 , the manufacturer, may wait for some period of time before revealing the plain-text message M to the destination point, generally the expected time of delivery, to prevent attempts to forge labels by counterfeiters or other entrusted intermediate points in the supply chain. 
       FIG. 7  shows an alternative embodiment of the present invention, similar to the first embodiment illustrated in  FIG. 6 . In the embodiment shown in  FIG. 7 , the encryption key e  702  is divided into three different portions  703 - 705 . One portion  705  is incorporated into the labels of pharmaceutical-containing bottles, such as label  706 . Another portion of the encryption key  704  is encoded into a label  708  affixed to a package containing bottles of the pharmaceutical. When the shipment is received at a destination node, one portion  705  of the encryption key is extracted from a bottle label  710 , and another portion  704  of the encryption key e is extracted from the label  708  affixed to the package containing the pharmaceutical bottles. Reconstruction of the encryption key e and decryption of the encrypted message C provides a computed, plain-text message M C  which can be compared with a copy of the message M R    716  received directly from the source node to authenticate the particular bottle  712  from which a portion  705  in the encryption key was extracted within the package  707 . In other words, by placing portions of the encryption key in different nested levels of packaging, the objects within the most deeply nested level of packaging can be authenticated. The same technique can be used to individually authenticate each pharmaceutical bottle within the package. Similarly, although not shown in  FIG. 7 , a portion of the encryption key may be incorporated within a pill or gelatin capsule in order to authenticate individual pills and gelatin capsules, in the pharmaceutical-supply-chain context discussed above with reference to  FIGS. 1 and 2 . 
       FIG. 8  is a control-flow diagram representing steps undertaken by a source point, or manufacturer, in order to secure a shipment according to one embodiment of the present invention. In step  802 , the source point selects a symmetrical encryption key e, a plain-text message M, and divides the key into n pieces, e 1 , e 2 , . . . e n . In addition, the source point generates an encrypted version of the message M, referred to as C, using the selected encryption key e. The source point, in step  804 , then incorporates at most n−1 portions of the encryption key into n−1 labels or n−2 labels and each packaged object, includes the encrypted message C in at least one label, and labels the shipment using the labels, preserving at least one portion of the encryption key e 1  as a secret. Next, in step  806 , the source point determines a time delay t to wait before revealing the plain-text message M to the destination node. In step  808 , the shipment is sent into the supply chain for eventual delivery to the destination point. In step  810 , the source point waits for the pre-computed time t. Finally, in step  812 , the source point sends or reveals the plain-text message M and the portions of the encryption key not incorporated in the shipment, including key-portion e 1 , to the shipment recipient. 
       FIG. 9  is a control-flow diagram representing steps undertaken by a shipment recipient in order to authenticate a shipment according to one embodiment of the present invention. In step  902 , the recipient receives the shipment and extracts from labels or objects within the shipment the encrypted message C and the portions of the encryption key incorporated within the shipment. As discussed above, the encryption keys and, optionally, the encrypted message C may be encoded by printing-feature variants used to print labels. Then, in the for-loop of steps  906 - 911 , the recipient of this shipment may individually authenticate each item at the deepest level of key-portion incorporation within the shipment. First, in step  907 , the encryption key e is reassembled from portions of the encryption key extracted from the labels and objects within a shipment and from a remaining portion or portions of the encryption key, including key-portion e 1 , directly received from the source point. The reassembled encryption key is then used to decrypt encrypted message C to produce a computed, plain-text message M C . In step  908 , the shipment recipient determines whether the computed plain-text message M C  is equal to a copy of the plain-text message M R  directly received from the source point. If the two are identical, as determined in step  908 , then the item is noted to have been authenticated, in step  909 . Otherwise, the item is noted to not be authenticated, in step  910 . When no more items remain to be authenticated, as determined in step  911 , the indications of whether items are authenticated or not are provided 912 to allow individual items to be accepted or rejected by the shipment recipient. 
     A different encryption key e key and message are generally used for each shipment, to prevent counterfeiters from intercepting the key and/or message in order to defeat authentication in a future shipment. The message may be altered by appending random bits to a previously used message. 
     Although the present invention has been described in terms of particular embodiments, it is not intended that the invention be limited to these embodiments. Modifications within the spirit of the invention will be apparent to those skilled in the art. For example, any of a large number of different encryption techniques may be used, providing that the encryption techniques use an encryption key that may be encoded into packaging labels and into packaged objects. Encryption schemes that use more than one key may also be used, such as public-key encryption schemes. The source point, or manufacturer, may wait for any of various different times before revealing the plain-text message and encryption-key piece to the destination point, depending on various considerations. In many cases, the plain-text message may be revealed ahead of time, since lacking the encryption-key piece withheld by the source point, a counterfeiter would be unable to produce labeling that would allow the destination point to reconstruct a valid encryption key. Encryption keys may be encoded by the method discussed above with reference to FIGS.  4  and  5 A-B, but may be encoded in other ways, such as electronically encoded into electronic devices associate with the shipment, or may be directly numerically or textually printed on labels, objects, packaging, or other portions of the shipment. The authentication method of the present invention may be used for authentication of a shipment between any two points in a supply chain, including between a first intermediate point, such as a distributor, and a second intermediate point, such as another distributor. Encryption keys and labels may be prepared by entities other than source points for use by source and destination points. Although a pharmaceutical-supply-chain context is used for the above description of the present invention, the method of the present invention may be used to secure shipment of any type of object, including electronic transmission of information objects through networks. 
     The foregoing description, for purposes of explanation, used specific nomenclature to provide a thorough understanding of the invention. However, it will be apparent to one skilled in the art that the specific details are not required in order to practice the invention. The foregoing descriptions of specific embodiments of the present invention are presented for purpose of illustration and description. They are not intended to be exhaustive or to limit the invention to the precise forms disclosed. Obviously many modifications and variations are possible in view of the above teachings. The embodiments are shown and described in order to best explain the principles of the invention and its practical applications, to thereby enable others skilled in the art to best utilize the invention and various embodiments with various modifications as are suited to the particular use contemplated. It is intended that the scope of the invention be defined by the following claims and their equivalents: