FIELD
The present disclosure generally relates to representing scalar digital
assets using hash chains, specifically the use ofhash chains to enable auditable
10 traceability of scalar digital assets in an offline environment.
BACKGROUND
In recent times, digital currencies have seen increased usage over
traditional fiat cmTencies. Many digital currencies utilize blockchain technology to
reduce the chances of the so-called "double-spend" problem. Double-spending is the
15 risk that a digital currency can be spent twice by a digital currency holder who can
manipulate the network to his/her advantage. Blockchain technology prevents this
"double-send" problem using an immutable shared ledger where each transaction is
confinned and verified by the blockchain network in the order the transactions occur.
Thus, the first spend of a digital currency would be confirmed and verified before the
20 second "double" spend, which would be identified as invalid by the blockchain
network. However, current technologies require the digital currency to be connected
to the blockchain network in order for such double-spend security mechanism to
work.
A technical problem inherent to most asset-based systems is how one
25 can uniquely identify individual assets efficiently. While unique identifiers can be
randomly chosen, there has to be a way to check for and avoid conflicts, and if large
numbers of assets are being conveyed, the data stream can become prohibitively large.
Hence, there is a need for a way to uniquely identify individual assets without fear of
conflicts while providing the ability to identify potentially large numbers of assets by
30 range or groups, etc.
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SUMMARY
The present disclosure provides a description of exemplary systems
and methods tor representing scalar digital assets using hash chains. The methods and
systems may include a processor which may receive a data request for one or more
5 units of a scalar digital asset from a computing device. The processor may identify the
scalar digital asset requested by the computing device and the one or more units of the
scalar digital asset. The processor may verify the computing device has access to the
scalar digital asset. The processor may generate a hash chain of the one or more units
of the scalar digital asset and transmit a data response message containing the hash
10 chain of the one or more units of the scalar digital asset to the computing device.
15
BRIEF DESCRIPTION OF THE DRAWING FIGURES
The scope of the present disclosure is best understood from the
toll owing detailed description of exemplary embodiments when read in conjunction
with the accompanying drawings. Included in the drawings are the following fihrures:
FIG. 1 is a block diagram illustrating a high level system architecture
for performing representation of scalar digital assets using hash chains.
FIG. 2 is a block diagram illustrating a computing system of the
system of FIG. 1 for performing representation of scalar digital assets using hash
chains in accordance with exemplary embodiments.
20 FIG. 3 is a flow diagram illustrating a process for representing scalar
25
digital assets using hash chains in the system of FIG. 1 in accordance with exemplary
embodiments.
FIG. 4 is a f1ow chart illustrating exemplary methods for representing
scalar digital assets using hash chains in accordance with exemplary embodiments.
FIG. 5 is a block diagram illustrating a computer system architecture in
accordance with exemplary embodiments.
Further areas of applicability of the present disclosure wi 11 become
apparent from the detailed description provided hereinafter. It should be understood
that the detailed description of exemplary embodiments are intended for illustration
30 purposes only and are, therefore, not intended to necessarily limit the scope of the
disclosure.
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DETAILED DESCRIPTION
Glossary ofTerms
PCT /US2021/022 710
Blockchain-A public ledger of all transactions of a blockchain-based
currency. One or more computing devices may comprise a blockchain network, which
5 may be configured to process and record transactions as part of a block in the
blockchain. Once a block is completed, the block is added to the blockchain and the
transaction record thereby updated. In many instances, the blockchain may be a ledger
of transactions in chronological order, or may be presented in any other order that
may be suitable for use by the blockchain network. In some configurations,
10 transactions recorded in the blockchain may include a destination address and a
currency amount, such that the blockchain records how much currency is attributable
to a specific address. In some instances, additional infonnation may be captured, such
as a source address, timestamp, etc. In some embodiments, a blockchain may also
consist of additional, and in some instances arbitrmy, data that is confirmed and
15 validated by the blockchain network through proof of work and/or any other suitable
verification techniques associated therewith. In some cases, such data may be
included in the blockchain as part of transactions, such as included in additional data
appended to transaction data. In some instances, the inclusion of such data in a
blockchain may constitute a transaction. In such instances, a blockchain may not he
20 directly associated with a specific digital, virtual, fiat, or other type of CUITency.
System for Representation of Scalar Digital Assets Using Hash Chains
FIG. 1 illustrates a system 100 for the representation of scalar digital
assets using hash chains.
In the system 1 00, a computing device 1 02 may operate as a client device and
25 communicate with a processing server 104. In an exemplary embodiment, the
processing server l 04 may operate as, but is not limited to, a scalar digital asset
moderator and/or regulator. For example, the processing server 104 may operate as a
currency moderator, such as, but not limited to, a bank or other financial institution.
Other types of assets would have other moderators, e.g., content providers or licensing
30 authorities for instance. The computing device 102 and processing server 104 may be
any type of computing system that is specially configured to perform the functions
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discussed herein, such as the computing system 200 illustrated in FIG. 2 or the
computing system 500 illustrated in FIG. 5, as discussed in more detail below.
In the system 1 00, the computing device 102 may electronically
transmit a data request 106 to the processing server 104. In an exemplary
5 embodiment, the data request 106 may be for a scalar digital asset stored on the
blockchain network 110. A scalar asset may be any asset such as, but not limited to, a
digital, virtual, fiat, or other type of currency, a data file, or any other type of digital
asset that may be quantified using a real number. A scalar digital asset may be capable
of being broken down into one or more units that make up the whole scalar digital
10 asset. For example, the computing device may electronically transmit a data request
106 to the processing server 104 for twenty U.S. Dollars, i.e., the scalar digital asset,
which may be broken down into units of dollar and cents, e.g., two ten dollar bills,
four five dollar bills, twenty one dollar bills, or two thousand cents, mixtures thereof~
etc. Because the hash chain can be of virtually any length, the units would likely be
15 the smallest denomination. Further, the data request 106 may include credentials
associated with the computing device 102 such as, but not limited to, a username, a
password, an account number, or any other identifYing information, etc. l'he
computing device 102 may electronically transmit the data request 106 to the
processing server 104 using any suitable communication network such as, but not
20 limited to, the communications infrastructure 506 illustrated in FIG. 5
In the system 100, the processing server 104 may receive the data
request 1 06 for the scalar digital asset stored on the blockchain network 110. In an
exemplary embodiment, the processing server 104 may be a node associated with the
blockchain network 110 and configured to post blockchain transactions and/or blocks
25 ofblockchain transactions to a blockchain associated therewith. In other
embodiments, the processing server 104 may be configured to electronically
communicate with an intermediate computing device, which may be a node of the
blockchain network 110. Communications between the processing server 104 and the
blockchain network 110 and/or intermediate computing device may be performed
30 using any suitable communication network, such as, but not limited to, the Intemet.
The processing server 104 may verify the computing device 102 has
access to the requested scalar digital asset stored on the blockchain network 110. In an
embodiment, the processing server 1 04 may query a memory associated with the
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processing server 1 04 that stores a record of all assets associated with the computing
device 102. In another embodiment, the processing server may store credentials such
as but not limited to, a user name, account numbers, a private key an/or a public key
associated with the computing device 102 and the blockchain network 110 allowing
5 the processing server 104 to access assets associated with the computing device 1 02
stored on the blockchain network 110. For example, the processing server l 04 may
operate as a scalar digital asset moderator and/or regulator and thus control access to
the blockchain network 110 by the computing device 102.
The processing server 104 may identify one or more units of the scalar
10 digital asset requested in the data request 106. In exemplary embodiment, the
processing server 104 may identifY the smallest units of the requested digital scalar
asset. Continuing with the example above, if the data request 106 is for twenty U.S.
Dollars, the processing server 104 may identify two thousand units, representing the
two thousand cents, i.e., the smallest denomination of the U.S. Dollar, as the one or
15 more units of the requested scalar digital asset. In another embodiment, the processing
server 104 may identifY a defined unit of the requested scalable asset where the
defined unit is a unit larger than the smallest unit of the requested scalable asset.
Continuing with the example above, if the data request 106 is for twenty U.S. Dollars,
the processing server 104 may identity two units representing two ten dollar bills, four
20 units representing four five dollar bills, or twenty units representing twenty one dollar
bills, etc.
The processing server 104 generates a hash chain to represent the
scalar digital asset requested by the computing device 102 in the data request 106. A
hash chain is created by taking an initial value and applying a hashing algorithm to
25 generate a subsequent value, where the hash is a one-way hash, preventing any entity
from identifying the initial value from the subsequent value. This process is repeated
a large number of times, where the hash value that is created is subsequently hashed
over and over, creating a chain starting with the initial value that has thus been hashed
potentially thousands of times. For instance, the processing server 104 may generate
30 an initial secret value X. Once the initial secret value X is identified, the processing
server 104 may hash the initial value by applying a hashing algorithm thereto to
obtain a new hash value, refeiTed to herein as H(XO). The hashing algorithm may be
a one-way cryptographic hash function such that there is no way to identify X from
H(XO). Once the hash value H(XO) has been obtained, the processing server 104 may
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5
repeat the process by hashing the value again to obtain the hash value H(H(XO)), also
referred to herein as H(X1). The computing device 102 may continue to repeat the
process a large number, N, of times to arrive at a final value H(XN) in the hash chain
that would look something like this:
I xj~-------?-!~ H{XOJ ~-----1 ---?o!~ H(X1JI~---~~ H(X2ll~-------?oi+{Xs) I
xo X1 X2 X3 X4
In an exemplmy embodiment, the processing server 104 generates a
hash chain of the scalar digital asset requested by the computing device 102 by taking
a random secret value (X) and then applying an agreed hash digest function (H) for
each unit of the scalar digital asset. The random secret value (X) may be an initial
10 value that is randomly or pseudo-randomly generated, selected by the user of the
computing device 102, or otherwise identified using any suitable method. The hash
digest function may be any cryptographic hash function, such as but not limited to,
SHA-256. This process results in a deterministic and unique chain of connected
hashes. Continuing with the example above where the requested scalar digital asset is
15 twenty U.S. Dollars, the processing server 104 would apply the hash digest function
(H) two thousand times resulting in a hash chain that is two-thousand hashes long,
with each hash representing one cent. Therefore, each unit, e.g., cent, ofthe scalar
digital asset, e.g., twenty U.S. Dollars, would have a unique, immutable identifier in
the two-thousand hash hash chain.
20 The processing server 1 04 may electronically transmit a data response
message 108 to the computing device 102 with the requested data. Jn an exemplary
embodiment, the data response message 108 includes the hash chain of the requested
scalar digital asset. For instance, in the above example, the data response message
would include the two-thousand chain hash chain, which represents each cent of the
25 twenty U.S. Dollars requested by the computing device 102. In an exemplary
environment, the processing sever 1 04 transmits the hash chain of the requested scalar
digital asset to the computing device 102 for use in an offline environment. For
example, the computing device l 02 may transmit all or part of the scalar digital asset
to another computing device. Continuing with the above example, the computing
30 device may transmit all two-thousand units of the twenty U.S. Dollars, or a designated
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portion of the two-thousand units representing the twenty U.S. Dollars, e.g., onethousand
units representing ten U.S. Dollars, or one-hundred units representing one
U.S. Dollar.
Cunently, there is a need to support offline use cases where a shared
5 digital ledger, or blockchain, is not available to provide double spending protection.
The methods and system discussed herein allow the computing device 102 to transmit
the scalar digital asset represented by a hash chain to other computing devices in an
offline environment in a traceable and auditable way. Since each hash in the hash
chain represents a single unit ofthe scalar digital asset, each unit of the scalar digital
10 asset will retain its identity and will have a unique and immutable origin, the original
secret value X, no matter how many times each unit is transferred offline by the
computing device 102. Thus, the methods and systems discussed herein provide a
novel solution, not addressed by cunent technology, for an auditable and traceable
way to transfer scalar digital assets in an offline environment using hash chains.
15 Further, the methods and systems discussed herein provide for the unit-level tracing
of values via hash chains of scalar digital assets exchanged directly between users in
an offline environment.
Computing System
FIG. 2 illustrates an embodiment of a computing system 200, such as
20 may serve as the computing device 102 and/or processing server 104 in the system
100. It will be apparent to persons having skill in the relevant art that the embodiment
of the computing system 200 illustrated in FIG. 2 is provided as illustration only and
may not be exhaustive to all possible configurations ofthe computing system 200
suitable for performing the functions as discussed herein. For example, the computer
25 system 500 illustrated in FIG. 5 and discussed in more detail below may be a suitable
configuration ofthe computing system 200.
The computing system 200 may include a receiving device 202. The
receiving device 202 may be configured to receive data over one or more networks
via one or more network protocols. In some instances, the receiving device 202 may
30 be configured to receive data from computing devices 102, processing server 1 04, and
other systems and entities via one or more communication methods, such as radio
frequency, local area networks, wireless area networks, personal area networks,
cellular communication networks, Bluetooth, the Jnternet, etc. In some embodiments,
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the receiving device 202 may be comprised of multiple devices, such as different
receiving devices for receiving data over different networks, such as a first receiving
device for receiving data over a local area network and a second receiving device for
receiving data via the Intemet. The receiving device 202 may receive electronically
5 transmitted data signals, where data may be superimposed or otherwise encoded on
the data signal and decoded, parsed, read, or otherwise obtained via receipt of the data
signal by the receiving device 202. In some instances, the receiving device 202 may
include a parsing module for parsing the received data signal to obtain the data
superimposed thereon. For example, the receiving device 202 may include a parser
10 program configured to receive and transform the received data signal into usable input
for the functions performed by the processing device to carry out the methods and
systems described herein.
The receiving device 202 may be confi!,Ttlred to receive data signals
electronically transmitted by computing device 102 that may be superimposed or
15 otherwise encoded with data request 106. The receiving device 202 may also be
configured to receive data signals electronically transmitted by processing servers
104, which may be superimposed or othervvise encoded with data response messages
1 08, which may include a hash value.
The computing system 200 may also include a communication module
20 204. The communication module 204 may be configured to transmit data between
modules, engines, databases, memories, and other components of the computing
system 200 for use in perfom1ing the functions discussed herein. The communication
module 204 may be comprised of one or more communication types and utilize
various communication methods for communications within a computing device. For
25 example, the communication module 204 may be comprised of a bus, contact pin
connectors, wires, etc. In some embodiments, the communication module 204 may
also be confi!,Ttlred to communicate between internal components ofthe computing
system 200 and external components ofthe computing system200, such as externally
connected databases, display devices, input devices, etc. The computing system 200
30 may also include a processing device. The processing device may be configured to
perfonn the functions of the computing system 200 discussed herein as will be
apparent to persons having skill in the relevant art. In some embodiments, the
processing device may include and/or be comprised of a plurality of engines and/or
modules specially configured to perform one or more functions ofthe processing
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device, such as a querying module 214, verification module 216, generation module
218, etc. As used herein, the term "module" may be software or hardware particularly
programmed to receive an input, perform one or more processes using the input and
provides an output. The input, output, and processes perfonned by various modules
5 will be apparent to one skilled in the art based upon the present disclosure.
The computing system 200 may also include a memory 206. The
memory 206 may be configured to store data f(.)r use by the computing system 200 in
perfom1ing the functions discussed herein, such as public and private keys, symmetric
keys, etc. The memory 206 may be configured to store data using suitable data
10 formatting methods and schema and may be any suitable type of memory, such as
read-only memory, random access memory, etc. The memory 206 may include, for
example, encryption keys and algorithms, communication protocols and standards,
data fom1atting standards and protocols, program code for modules and application
programs of the processing device, and other data that may be suitable for use by the
15 computing system 200 in the performance of the functions disclosed herein as will be
apparent to persons having skill in the relevant art. In some embodiments, the
memory 206 may be comprised of or may otherwise include a relational database that
utilizes structured query language for the storage, identification, modifying, updating,
accessing, etc. of structured data sets stored therein. The memory 206 may be
20 configured to store, for example, cryptographic keys, salts, nonces, communication
information for the back-end system, etc.
The memory 206 may be configured to store a hash chain and data
associated therewith. In computing device 102, the memory 206 may store one or
more initial values and any hash chain values associated therewith. In the computing
25 device 102, the memory 206 may store a received hash chain as part of a transmitted
data response message 1 08 for use in an offline transfer of a scalar digital asset.
Further, in the computing device 102, the memory 206 may store any subsequent
transfers of one or more units of the scalar digital asset represented by the hash chain.
In the processing server 104, the memory 206 may store the random secret value X,
30 i.e., the initial value used to start the hash chain. The memory 206 of the processing
server 104 may store the public and private keys associated with the computing
device 102 for querying the blockchain network 110 for access to a scalar digital asset
requested by the computing device 102. Further, the memmy 206 of the processing
server 104 may store the hash chain created as part of a transmitted data response
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message 108 for use in an offline transfer of a scalar digital asset by the computing
device 102.
The computing system 200 may include a querying module 214. The
querying module 214 may be configured to execute queries on databases to identify
5 information. The querying module 214 may receive one or more data values or query
strings, and may execute a query string based thereon on an indicated database, such
as the memory 206 of the computing system 200 to identify information stored
therein. The querying module 214 may then output the identified infom1ation to an
appropriate engine or module of the computing system 200 as necessary. The
10 querying module 214 may, for example, execute a query on the memory 206 of the
computing system 200 to identify the requested scalar digital asset to be hashed into a
hash chain for inclusion in a data response message 108 to be transmitted to the
computing device 102. The querying module 214 may also, for example, execute a
query on the memory 206 of the computing system 200 to identifY one or more units
15 that make up a scalar digital asset associated with the computing device 102.
The computing system 200 may also include a verification module
216. The verification module 216 may be configured to perform verifications for the
computing system 200 as part of the functions discussed herein. The verification
module 216 may receive instructions as input, which may include data to be verified
20 and/or data to be used in the verification. The verification module 216 may perform a
verification as requested and may output a result of the verification to another module
or engine of the computing system 200. The verification module 216 may, for
example, be configured to verify that the computing device 102 has access to a
requested scalar digital asset stored on the blockchain net\'-rork 110.
25 The computing system 200 may also include a generation module 218.
The generation module 218 may be configured to generate data for use by the
computing system 200 in perfonning the functions discussed herein. The generation
module 218 may receive instructions as input, may generate data based on the
instructions, and may output the generated data to one or more modules of the
30 computing system 200. For example, the generation module 218 may be configured
to generate a hash chain via the application ofhash digest functions to initial values,
such as for use in representing a scalar digital asset, for transmission to a computing
device 102.
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The computing system 200 may also include a transmitting device 220.
The transmitting device 220 may be configured to transmit data over one or more
networks via one or more network protocols. In some instances, the transmitting
device 220 may be configured to transmit data to computing devices 102, processing
5 servers 104, blockchain networks 110 and other entities via one or more
communication methods, local area networks, wireless area networks, cellular
communication, Bluetooth, radio frequency, the Internet, etc. In some embodiments,
the transmitting device 220 may be comprised of multiple devices, such as different
transmitting devices for transmitting data over different networks, such as a first
10 transmitting device for transmitting data over a local area network and a second
transmitting device for transmitting data via the Intemet. The transmitting device 220
may electronically transmit data signals that have data superimposed that may be
parsed by a receiving computing device. In some instances, the transmitting device
220 may include one or more modules for superimposing, encoding, or otherwise
15 formatting data into data signals suitable for transmission.
The transmitting device 220 may be configured to electronically
transmit data signals to processing servers 104 that are superimposed or otherwise
encoded with data request 1 06, which may include data used in the functions as
discussed herein. The transmitting device 220 may also be configured to
20 electronically transmit data signals to computing device 102 that may be
superimposed or otherwise encoded with a data response message 1 08, such as may
include a hash chain representing a one or more units of a scalar digital asset or any
other information transmitted to the computing device 102 in response to a data
request 106.
25 Process for Representation of a Scalar Digital Asset Using Hash Chains
FIG. 3 illustrates an example process executed in the system 100 of
FIG. l for the representation of a scalar digital asset using a hash chain.
In step 302, the computing device 102 may electronically transmit
(e.g., via a transmitting device 220) a data request 106 to the processing server 104 to
30 start a communication session therewith using any suitable communication method.
In step 304, the processing server 104 may receive (e.g., via a receiving device 202)
the data request 106, where the data request may include a request for one or more
units of a scalar digital asset stored on the blockchain network 110.
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In step 306, the processing server 104 may identify (e.g., via a query
executed by a querying module 214) the scalar digital asset requested by the
computing device 102 on the blockchain network 110 via the data request 106.
Further, at step 308, the processing server may identify (e.g., via a query executed by
5 a querying module 214) the one or more tmits of the requested scalar digital asset. It
should be noted that a total of hash values can be identified by a range, e.g., "Xl-X4"
would identify four cents in one example, thus avoiding the need to identify X1, X2,
X3, X4. This greatly reduces the need to convey large numbers of assets using a
relatively small set of data values.
10 In step 310, the processing may verifY (e.g., via a query executed by a
querying module 214) that the computing device 1 02 has access to the requested
scalar digital asset stored on the blockchain network 110.
In step 312, the processing server may generate may (e.g., via a
generation module 218 thereof) a hash chain of the one or more identified units ofthe
15 requested scalar digital asset by applying a hash digest function using a random initial
value to each unit of the requested scalar digital asset.
In step 314, the processing server may transmit (e.g., via a transmitting
device 220) a data response message 108 to the computing device 102. At step 316,
the computing device 102 may receive (e.g., via a receiving device 202 thereof) the
20 data response message 108 containing the hash chain representing the scalar digital
asset requested in the data request 106.
Exemplary Method for Representing Scalar Digital Assets Using Hash Chains
FIG. 4 illustrates a method 400 for the representation of a scalar digital
asset using a hash chain in the perspective of the processing server 104 in the system
25 100 ofFIG. 1.
In step 402, a data request (e.g., data request 106) may be received
from a computing device (e.g., the computing device 1 02) by a receiver (e.g., the
receiving device 202) of a processing server (e.g., the processing server 1 04). The
data request may be for one or more units of a scalar digital asset stored on a
30 distributed ledger (e.g., the blockchain network 110) moderated and/or regulated by
the processing server 104.
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In step 404, the scalar digital asset requested by the computing device
(e.g., the computing device 102) may be identified by the processing server (e.g., via a
query executed by a querying module 214) on the distributed ledger.
In step 406, the processing server may identify by a processor (e.g., via
5 a query executed by a querying module 214) one or more units of the scalar digital
asset requested by the client device. The processing server may identify a number of
smallest units of the scalar digital asset or a designated unit size of the scalar digital
asset.
In step 408, the processing server may verify by a processor (e.g., the
10 verification module 216) that the computing device has access to the requested scalar
digital asset stored on the distributed ledger.
In step 410, the processing server may generate by a processor (e.g.,
the generation module 218) of the processing server, a hash chain by applying a hash
digest function to the one or more units of the scalar digital asset using a random
15 initial value. This results in a hash chain representing the requested scalar digital
asset by applying a hash digest function using a random initial value to each identified
unit of the requested scalar digital asset.
In step 412, a data response message (e.g., data response message 1 08)
containing the hash chain of the one or more units of the scalar digital asset may be
20 transmitted by the transmitter (e.g., the transmitting device 220) of the processing
server to the computing device.
Computer System Architecture
FIG. 5 illustrates a computer system 500 in which embodiments of the
present disclosure, or portions thereof, may be implemented as computer-readable
25 code. For example, the computing device 102 and processing server 104 of FIG. 1
and the computing system 200 of FIG. 2 may be implemented in the computer system
500 using hardware, software executed on hardware, firmware, non-transitory
computer readable media having instructions stored thereon, or a combination thereof
and may be implemented in one or more computer systems or other processing
30 systems. Hardware, software, or any combination thereof may embody modules and
components used to implement the methods of FIGS. 3-4.
If programmable logic is used, such logic may execute on a
commercially available processing platform configured by executable software code
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to become a specific purpose computer or a special purpose device (e.g.,
programmable logic array, application-specific integrated circuit, etc.). A person
having ordinary skill in the art may appreciate that embodiments of the disclosed
subject matter can be practiced with various computer system configurations,
5 including multi-core multiprocessor systems, minicomputers, mainframe computers,
computers linked or clustered with distributed functions, as well as pervasive or
miniature computers that may be embedded into viliually any device. For instance, at
least one processor device and a memory may be used to implement the above
described embodiments.
10 A processor unit or device as discussed herein may be a single
processor, a plurality of processors, or combinations thereof. Processor devices may
have one or more processor "cores." The terms "computer program medium," "nontransitory
computer readable medium," and "computer usable medium" as discussed
herein are used to generally refer to tangible media such as a removable storage unit
15 518, a removable storage unit 522, and a hard disk installed in hard disk drive 512.
Various embodiments of the present disclosure are described in terms
of this example computer system 500. After reading this description, it will become
apparent to a person skilled in the relevant art how to implement the present
disclosure using other computer systems and/or computer architectures. Although
20 operations may be described as a sequential process, some of the operations may in
fact be performed in parallel, concuJTently, and/or in a distributed environment, and
with program code stored locally or remotely for access by single or multi-processor
machines. ln addition, in some embodiments the order of operations may be
rearranged without departing from the spirit of the disclosed subject matter.
25 Processor device 504 may be a special purpose or a general purpose
processor device specifically configured to perform the functions discussed herein.
The processor device 504 may be connected to a communications infrastructme 506,
such as a bus, message queue. network, multi-core message-passing scheme, etc. The
network may be any network suitable for performing the functions as disclosed herein
30 and may include a local area network (LAN), a wide area network (WAN), a wireless
network (e.g., WiFi), a mobile communication network, a satellite network, the
Internet, tiber optic, coaxial cable, infrared, radio frequency (RF), or any combination
thereof. Other suitable network types and configurations will be apparent to persons
having skill in the relevant art. The computer system 500 may also include a main
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memory 508 (e.g., random access memory, read-only memory, etc.), and may also
include a secondmy memory 510. The secondary memmy 510 may include the hard
disk drive 512 and a removable storage drive 514, such as a f1oppy disk drive, a
magnetic tape drive, an optical disk drive, a i1ash memmy, etc.
5 The removable storage drive 514 may read from and/or write to the
removable storage unit 518 in a well-known manner. The removable storage unit 518
may include a removable storage media that may be read by and written to by the
removable storage drive 514. For example, ifthe removable storage drive 514 is a
floppy disk drive or universal serial bus poli, the removable storage unit 518 may be a
10 floppy disk or portable i1ash drive, respectively. In one embodiment, the removable
storage unit 518 may be non-transitory computer readable recording media.
In some embodiments, the secondary memory 51 0 may include
altemative means for allowing computer programs or other instructions to be loaded
into the computer system 500, for example, the removable storage unit 522 and an
15 interface 520. Examples of such means may include a program cartridge and
cartridge interface (e.g., as found in video game systems), a removable memory chip
(e.g., EEPROM, PROM, etc.) and associated socket, and other removable storage
units 522 and interfaces 520 as will be apparent to persons having skill in the relevant
art.
20 Data stored in the computer system 500 (e.g., in the main memory 508
and/or the secondary memory 51 0) may be stored on any type of suitable computer
readable media, such as optical storage (e.g., a compact disc, digital versatile disc,
Blu-ray disc, etc.) or magnetic tape storage (e.g., a hard disk drive). The data may be
configured in any type of suitable database configuration, such as a relational
25 database, a structured que1y language (SQL) database, a distributed database, an
object database, etc. Suitable configurations and storage types will be apparent to
persons having skill in the relevant art.
The computer system 500 may also include a communications
interface 524. The communications interface 524 may be configured to allow software
30 and data to be transfe1Ted between the computer system 500 and external devices.
Exemplary communications interfaces 524 may include a modem, a network interface
(e.g., an Ethernet card), a communications port, a PCMCIA slot and card, etc.
Software and data transferred via the communications interface 524 may be in the
form of signals, which may be electronic, electromagnetic, optical, or other signals as
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will be apparent to persons having skill in the relevant art. The signals may travel via
a communications path 526, which may be confif:,rured to cany the signals and may be
implemented using wire, cable, fiber optics, a phone line, a cellular phone link, a
radio frequency link, etc.
5 The computer system 500 may further include a display interface 502.
The display interface 502 may be configured to allow data to be transferred between
the computer system 500 and extemal display 530. Exemplmy display interfaces 502
may include high-definition multimedia interface (HDMI), digital visual interface
(DVI), video graphics array (VGA), etc. The display 530 may be any suitable type of
10 display for displaying data transmitted via the display interface 502 of the computer
system 500, including a cathode ray tube (CRT) display, liquid crystal display (LCD),
light-emitting diode (LED) display, capacitive touch display, thin-film transistor
(TFT) display, etc.
Computer program medium and computer usable medium may refer to
15 memories, such as the main memory 508 and secondary mem01y 510, which may be
memory semiconductors (e.g., DRAMs, etc.). These computer program products may
be means for providing software to the computer system 500. Computer programs
(e.g., computer control logic) may be stored in the main memory 508 and/or the
secondary memory 510. Computer programs may also be received via the
20 communications interface 524. Such computer programs, when executed, may enable
computer system 500 to implement the present methods as discussed herein. In
particular, the computer programs, when executed, may enable processor device 504
to implement the methods illustrated by FIGS. 3-4, as discussed herein. Accordingly,
such computer programs may represent controllers of the computer system 500.
25 Where the present disclosure is implemented using software, the software may be
stored in a computer program product and loaded into the computer system 500 using
the removable storage drive 514, interface 520, and hard disk drive 512, or
communications interface 524.
The processor device 504 may comprise one or more modules or
30 engines configured to perform the functions of the computer system 500. Each ofthe
modules or engines may be implemented using hardware and, in some instances, may
also utilize software, such as corresponding to program code and/or programs stored
in the main memory 508 or secondary memory 510. In such instances, program code
may be compiled by the processor device 504 (e.g., by a compiling module or engine)
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prior to execution by the hardware of the computer system 500. For example, the
program code may be source code ·written in a programming lan&TUage that is
translated into a lower level language, such as assembly language or machine code,
for execution by the processor device 504 and/or any additional hardware components
5 of the computer system 500. The process of compiling may include the use of lexical
analysis, preprocessing, parsing, semantic analysis, syntax-directed translation, code
generation, code optimization, and any other techniques that may be suitable for
translation of program code into a lower level language suitable for controlling the
computer system 500 to perform the functions disclosed herein. It will be apparent to
10 persons having skill in the relevant art that such processes result in the computer
system 500 being a specially configured computer system 500 uniquely programmed
to perform the functions discussed above.
Techniques consistent with the present disclosure provide, among
other features, systems and methods for authentication of a client device using a hash
15 chain. While various exemplmy embodiments of the disclosed system and method
have been described above it should be understood that they have been presented for
purposes of example only, not limitations. It is not exhaustive and does not limit the
disclosure to the precise form disclosed. Modifications and variations are possible in
light of the above teachings or may be acquired from practicing of the disclosure,
20 without depmiing from the breadth or scope.

WHAT IS CLAIMED IS:
1. A method for representing scalar digital assets using hash chains, the
method comprising:
receiving, by a receiver of a processing server, a data request for one or more
units of a scalar digital asset from a computing device;
identifying, by a processor of the processing server, the scalar digital asset
requested by the computing device;
identifying, by a processor of the processing server, the one or more units of
10 the scalar digital asset;
verifYing, by a processor of the processing server, the computing device has
access to the scalar digital asset;
generating, by the processor of the processing server, a hash chain of the one
or more units of the scalar digital asset; and
15 transmitting, by a transmitter of the processing server, a data response
message containing the hash chain of the one or more units of the scalar digital asset
to the computing device.
2. The method of claim 1, wherein generating, by the processor of the
20 processing server, a hash chain of the one or more tmits ofthe scalar digital asset
further comprises:
applying, by the processor of the processing server, a hash digest function to
each of the one or more units of the scalar digital asset using a random initial value.
25 3. The method of claim 2, wherein each unit of the one or more units of the
30
scalar digital asset is represented by a single hash in the hash chain.
4. The method of claim 2, wherein a range of the one or more units of the
scalar digital asset is represented by a stmi hash and an end hash.
5. The method of claim 1, wherein the scalar digital asset is a digital currency.
6. The method of claim 1, wherein one unit of the one or more units of the
scalar digital asset is the smallest unit of the scalar digital asset.
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7. The method of claim 1, wherein one unit of the one or more units of the
scalar digital asset is a designated unit size of the scalar digital asset.
8. The method of claim 1, wherein the scalar digital asset is stored on a
5 blockchain network.
10
9. The method of claim 1, wherein the hash chain is transferrable in an oft1ine
enviro1m1ent by the first computing device to a secondmy computing device.
10. The method of claim 1, wherein a designated ra11ge of the hash chain is
transferrable in an offline environment by the first computing device to a secondary
computing device.
11. A system for representing scalar digital assets using hash chains, the
15 system comprising:
one or more processors, one or more computer-readable memories, one or
more computer-readable tangible storage devices, and instructions stored on at least
one of the one or more storage devices fbr execution by at least one of the one or
more processors via at least one of the one or more memories. the instructions
20 comprising:
instructions to receive, by a receiver of a processing server, a data request for
one or more units of a scalar digital asset from a computing device;
instructions to identify, by a processor of the processing server, the scalar
digital asset requested by the computing device;
25 instructions to identify, by a processor of the processing server, the one or
more units of the scalar digital asset;
instructions to verify, by a processor of the processing server, the computing
device has access to the scalar digital asset;
instructions to generate, by the processor of the processing server, a hash chain
30 of the one or more units of the scalar digital asset; and
instructions to transmit, by a transmitter of the processing server, a data
response message containing the hash chain of the one or more units of the scalar
digital asset to the computing device.
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12. The system of claim 11, wherein the instructions to generate, by the
processor of the processing server, a hash chain of the one or more units of the scalar
digital asset further comprise:
instructions to apply, by the processor ofthe processing server, a hash digest
5 function to each of the one or more units of the scalar digital asset using a random
initial value.
10
13. The system of claim 12, wherein each unit of the one or more units of the
scalar digital asset is represented by a single hash in the hash chain.
14. The system of claim 12, wherein a range of the one or more units of the
scalar digital asset is represented by a start hash and an end hash
15. The system of claim 11, wherein the scalar digital asset is a digital
15 currency.
20
25
16. The system of claim 11, wherein one unit of the one or more units of the
scalar digital asset is the smallest unit of the scalar digital asset.
17. The system of claim 11, wherein one unit of the one or more units of the
scalar digital asset is a designated unit size of the scalar digital asset.
18. The system of claim 11, wherein the scalar digital asset is stored on a
blockchain network.
19. The system of claim ll, wherein the hash chain is transferrable in an
offline environment by the first computing device to a secondary computing device.
20. The system of claim 11, wherein a designated range of the hash chain is
30 transferrable in an offline environment by the first computing device to a secondary
computing device.