CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims priority to and the benefit of the filing date of
European Patent Application No. 16153521.6, filed January 29, 2016, which is hereby
incorporated by reference in its entirety.
5 FIELD OF DISCLOSURE
This disclosure relates generally to digital asset conversion. In
embodiments, the disclosure relates to an infrastructure enabling digital assets such as
virtual currency (cryptocurrency) to be converted to allow transactions is governmentbacked
"flat" currency.
10 BACKGROUND OF DISCLOSURE
A virtual currency (also known as a digital currency) is a medium of
exchange implemented through the Internet generally not tied to a specific
government-backed "flat" (printed) currency such as the US dollar or the Euro and
typically designed to allow instantaneous transactions and borderless transfer of
15 ownership. The best known type of virtual currency is cryptocurrency, in which
cryptography is used to secure transactions and to control the creation of new units.
Several cryptocurrencies exist, of which the best known is Bitcoin. Bitcoin is
decentralized in the sense that it has no central point of control. Transactions are
recorded on a public ledger in the fonn of a block chain ~ a distributed database
20 maintaining a continuously growing list of transaction data records. Cryptographic
processes are used tp harden the block chain against tampering and revision.
Decentralization and a public ledger are typical features of cryptocurrencies.
Virtual currency is one type of electronic money~ more generally,
electronic money is any electronically stored money balance such as a money balance
25 stored on a physical card with an embedded processor or adapted for transfer over a
computer network. Electronic money based on a flat currency is typically centralized
in that there is a central point of control over the money supply. Pay Pal is an example
of an electronic money system with centralized control, and systems such as Go ogle
Wallet and Apple Pay enable electronic money transactions using mobile devices.
30 At present, while cryptocurrencies are widely used in online
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5
communities, they are not generally used by "bricks and mortar" retailers. It would
be desirable to allow wider use of cryptocurrencies in conventional transaction
infrastructures as generally used by merchants.
SUMMARY OF DISCLOSURE
In a first aspect, the disclosure provides a computer-implemented
service for converting digital assets into a transaction currency for use by a payment
device in a transaction system that is not adapted for transactions using the digital
assets, the service using a server with a suitably programmed processor adapted to:
monitor a transaction currency balance in a user account associated with the payment
10 device, and to compare the transaction currency balance with rules for maintaining the
transaction currency balance; and where required to do so by the rules, instructing
conversion of user digital assets at one or more exchanges into the transaction
currency to maintain the transaction currency balance.
The payment device may be associated with an issuing bank, and the
15 computer-implemented service may be adapted to receive the transaction currency
balance from the issuing bank. The computer-implemented service may be adapted to
receive details of transactions from the user account in the transaction currency from
the issuing bank or the transaction system.
Instructing conversion of digital assets into the transaction currency at
20 the one or more exchanges may comprise instructing the one or more exchanges to
make a conversion transaction on behalf of an owner of the digital assets.
Instructing conversion of digital assets into the transaction currency at
the one or more exchanges comprises advising an owner of the digital assets to make
a conversion transaction at the one or more exchanges.
25 The digital assets may comprise cryptocurrency.
In a second aspect, the disclosure provides a method of converting
digital assets into a transaction currency for use in a transaction system that is not
adapted for transactions using the digital assets, the method comprising: storing
digital assets for use with one or more exchanges adapted for conversion of the digital
30 assets into the transaction currency; establishing a balance in the transaction currency
for use by a payment device, and establishing rules for maintaining the transaction
currency balance; and when required by the rules for maintaining the transaction
currency balance, instructing conversion of digital assets into the transaction currency
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at the one or more exchanges for maintaining the transaction currency balance in the
transaction currency for use by the payment device.
The digital assets may comprise cryptocurrency assets. The rules may
comprise converting digital assets when the transaction currency balance falls below a
5 predetermined level, or converting digital assets after a transaction in the transaction
currency to maintain the transaction currency balance at a predetennined level.
Establishing the transaction currency balance may comprise converting
digital assets to provide a predetermined transaction currency balance.
Instructing conversion of digital assets into the transaction currency at
1 0 the one or more exchanges may comprise instructing the one or more exchanges to
make a conversion transaction on behalf of an owner of the digital assets.
Instructing conversion of digital assets into the transaction currency at
the one or more exchanges may comprise advising an owner of the digital assets to
make a conversion transaction at the one or more exchanges.
15 BRIEF DESCRIPTION OF FIGURES
Embodiments of the disclosure will now be described, by way of
example, with reference to the accompanying Figures, of which:
Figure 1 shows a conventional transaction infrastructure by which
trans~ctions are made using payment devices;
20 Figure 2 shows a mobile computing device adapted for use with the
infrastructure of Figure 1;
Figure 3 shows an exemplary existing virtual currency infrastructure;
Figure 4 shows an exemplary existing virtual currency infrastructure
using an exchange service;
25 Figure 5 shows a modified transaction infrastructure according to an
embodiment ofthe disclosure linking elements of the conventional transaction
infrastructure ofFigure 1 with the virtual currency infrastructure ofFigures 3 and 4;
Figure 6 shows a structure of user accounts indicated at the location of
account provider in the infrastructure of Figure 5;
30 Figure 7 shows an exemplary method of use of a payment device
according to an embodiment of the disclosure; and
Figure 8 shows steps in an exemplary transaction using the
infrastructure ofFigure 5.
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DESCRIPTION OF SPECIFIC EMBODIMENTS
Specific embodiments of the disclosure will be described below with
reference to the Figures. Before embodiments of the disclosure are described, a
conventional transaction infrastructure architecture will be described with reference to
5 Figure 1 and an exemplary virtual currency architecture will be described with
reference to Figure 2.
In the conventional transaction infrastructure architecture of Figure 1, a
user (not shown) is provided with a payment device- this may be for example a
payment card 2, but it may also be a computing device (such as a mobile phone 1 ).
10 This computing device comprises a mobile payment application that allows use of a
payment card - this may be either as a proxy for an existing physical card, or of an
entirely virtual card - in either case, the mobile payment application may be
considered to act for a "digitized" card. The mobile payment application comprises a
cardlet (held securely, for example in a mobile phone SIM) performing card functions
15 and is associated a wallet allowing user manag~ment of cards and accounts.
Mobile phone 1 is also shown as the mechanism for the user to interact
with other elements of the system over a suitable network 5 - network 5 here
represents any appropriate communication network for the communication path
indicated, and may be the public internet, a cellular communications network or a
20 private network, depending on the parties involved in the communication and the
I
need for the communication path to be secure.
The payment device is adapted for transaction with a point of
interaction (POI) tennina14 such as a point of sale (POS) terminal or an automated
teller machine (ATM) and transactions may also be conducted with an online
25 merchant 3. The payment card 2 will typically include a chip and a wireless
transmitter and receiver adapted for short range communication by protocols such as
those defined under ISO/IEC 14443- if used as a payment device, the mobile phone 1
(which will typically be adapted to implement short range communication under the
NFC standard) must have similar capability and an appropriate payment application
30 installed.
There is a network connection between the user computer devices and
a card issuing bank 5 or system associated with the user. A banking infrastructure 7
will also connect the card issuing 5 and the merchant's transaction acquiring bank 6,
allowing transactions to be carried out between them. This banking infrastructure will
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typically be provided by a transaction card provider who provides transaction card
services to the card issuing bank 5. The banking infrastructure 7 provides
authorization at the time of purchase, clearing of the transaction and reconciliation
typically within the same working day, and settlement of payments shortly after that.
5 The banking infrastructure 7 comprises a plurality of switches, servers and databases,
and is not described further here as the details of the banking infrastructure used are
not necessary for understanding how embodiments of the disclosure function and may
be implemented, save to note that associated with the banking infrastructure 7 is a
digital enablement service 17 adapted to support use of digitized cards, for example
10 through EMV tokenisation protocols. As noted, the mobile phone comprises a wallet
to enable user management of accounts (and, typically, aspects of security of the
device) - to avoid confusion with other uses of the term wallet in this specification,
this will be referred to as a "payment device wallet" below.
Using this approach, a computing device- shown as a mobile device
15 in Figure 1, but not necessarily so- is adapted to make "electronic money"
transactions using "flat" money over a conventional transaction infrastructure.
Elements of such a computing device are shown in Figure 2.
Figure 2 shows a mobile phone 1, though it should be noted that any
other portable computing apparatus such as a laptop, notebook or tablet computer can
20 be used as computing apparatus in embodiments of the disclosure. The mobile phone
comprises a processor 201 and a memory 202, such that the memory stores and the
processor will subsequently run applications (shown generally as application space
203) such as a payment application 203a. The mobile phone has a user interface
comprising a display 204 and a touchscreen 205 (or other input device) and associated
25 drivers to allow a user to enter data into and view information from the applications
203. The mobile phone 1 also has a cellular telecommunications capability, including
subscriber information module (SIM) 206 and wireless communication element 207
together providing the ability to connect to a cellular communications network. The
mobile phone may need to perform cryptographic operations in order to interact
30 securely with a POS terminal- this may be achieved more securely by a
cryptographic capability within the subscriber information module 206, such as a
cryptographic processor in a tamperproof element- another approach is to manage
without a secure element by using Host Card Emulation (HCE). Implementation of
HCE in Android is discussed at
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https://developer.andr:oid.com/guide/topics/connectivity/nfc/hce.html - other operating
systems are developing or have developed similar approaches. In other kinds of
computing devices other forms of tamper resistant hardware may be used to increase
the security of cryptographic processing and sensitive data. The mobile phone is here
5 shown as having a local networking element 208 as well, in order to establish a short
range wireless network connection - however, in other embodiments the mobile
phone 1 may only be able to make network connections through a cellular
telecommunications network. Where the computing device is not a mobile phone,
then while a network connection is needed to enable communication between the
1 0 computing device and other system elements, this need not involve cellular
telecommunications. For example, the computing device may be a tablet computer
without cellular telecommunications capability but capable of making a local wireless
network connection.
Figure 3 shows a plurality of computing devices interacting through a
15 peer-to-peer network 31 implemented over the internet 5-in this case, these
computing devices include mobile phone 1, along with online merchant 3 and an
exemplary user computing device 32 (of very many others in the network). One user
computing device 33 is adapted for mining new currency - a process briefly discussed
below. Each computing device has a cryptocurrency client 34 for key generation and
20 sending and receiving payments and a cryptocurrency data directory 35. The data
directory comprises block chain information 36 and the user's cryptocurrency wallet
37. Other elements shown are the online merchant's storefront application 38, shown
adjacent to the merchant's cryptocurrency client 34 as the two interact together to
allow cryptocurrency payments to be made to the merchant 2. The other element
25 shown is a mining engine 39 shown as part of the mining user computing device 33-
again, mining user computing device 33 is representative of many others on the
system. The roles of each element of the system will be briefly described below, but
for detailed description of individual cryptocurrency systems the skilled person will
consult appropriate resources - for example, the Bitcoin wiki found at
30 https://en.bitcoin.itlwiki/Main Page.
Information personal to the user is kept in the cryptocurrency wallet
3 7. This contains one or more addresses for the user - these are alphanumeric
identifiers that represent a possible destination for a cryptocurrency payment to that
user. A user can typically generate a new address at no cost -typically an address is a
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single use token for a specific transaction. The wallet also contains the user's
cryptographic keys. An address is a public key corresponding to one of the user's
private keys -the user can generate new key pairs as needed from a base key. The
wallet also contains the user's accounts- when cryptocurrency is received, it is
5 assigned to an account. Other cryptocurrency structures are possible (for example,
addresses and accounts can be conflated in some cryptocurrency types), but the
exemplary approach described here is widely used.
Block chain information 36 is public and is shared on a peer-to-peer
basis, but provides a mechanism for verification of transactions as described below.
10 The block chain itself is a transaction database shared by all nodes of the network- a
full copy of the block chain for a cryptocurrency contains every transaction ever
executed, allowing the determination of values associated with any given address.
The blocks are chained, as each block contains a hash of the previous block. Once a
block is mature in the chain, it is not practical to modify it computationally because
15 each later block would have to be regenerated.
A typical transaction involving a payment from Alice to Bob operates
in the following way. Bob creates a new address using the cryptocurrency client, and
provides the address (a public key for a private key held by Bob) to Alice as a
destination for the payment. Alice makes the transaction using her cryptocurrency
20 client by indicating a payment to the address indicated by Bob from one of her own
addresses -this is done by signing a transaction request with her private key for the
address, the public key being usable to establish that the transaction was sent by Alice
to Bob's address. Transaction requests are broadcast across the system for
incorporation into a transaction block.
25 A new block is established by "mining". This is a process in which a
candidate for a block is determining the answer to a computationally difficult problem
relating to the last block on the chain- typically achieving a particular result for a
hash function on that last block using a nonce value, the computational difficulty
arising from there being a large number of possible nonce values and no way other
30 than brute force of determining which nonce will achieve the desired result. Once a
miner has a valid block, this can be added to the block chain - it will typically contain
a reward for the miner (an agreed number of cryptocurrency units assigned to a
miner's address). A miner may also be rewarded for transactions added to the new
block. The new block chain with the additional added block (including Alice's
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payment to Bob) is broadcast around the network.
The transaction cannot immediately be considered verified by virtue of
its inclusion in the latest block. However, when further blocks are added, it becomes
effectively impossible to tamper with the transaction record, as this could only be
5 done by regeneration of subsequent blocks. The transaction can be considered to be
verified at this stage.
This type of transaction can be termed "on~the~chain" ~it is on the
public record and requires the existence of miners to verify it. On-the~chain
transactions have a unique wallet address which is the public key string of a
10 cryptographic key pair (generated for example by Elliptic Curve Cryptograppy). It is
also possible to have "off~the~chain" transactions for which there is no public record.
This may be achieved with a database (such as MS-SQL, MySQL, Oracle etc.)
containing a representation of holdings with balance swaps possible between different
holdings retained in the database. For example, Coinbase or Bitstamp does not move
15 bitcoins on the chain for internal reconciliation but just initiates a balance change on
their database of users' holdings.
In order to prevent risk of loss, many users prefer to keep
cryptocurrency funds offline and to have their use of cryptocurrency mediated by a
service. To achieve this, many use shared wallet services from providers such as
20 Bitstamp and Coinbase. These do not change the basic transaction mechanism of the
cryptocurrency, but provide transaction services for a user by establishing an address
and sending cryptocurrency on behalf of the user, often in return for a flat currency
payment (in which case these services are also operating as an exchange).
Figure 4 illustrates the architecture of Figure 3 showing an exchange
25 service, here also acting as a shared wallet service. The peer~ to~ peer network of
Figure 4 may contain all the node types shown in Figure 3, though for convenience
not all types of node shown in Figure 3 are shown in Figure 4. Figure 4 shows two
new types of node~ a shared wallet service node 42, and a shared wallet user node
41.
30 The shared wallet user node 41 does not itself need to hold
cryptocurrency and therefore does not need to operate as a peer~to~peer network node,
but may for example have a client/server relationship with the shared wallet service
node 42. A shared wallet client application 411, preferably with secured memory 412
(in embodiments where private keys are to be held by the user) is used to
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communicate with the shared wallet service.
The shared wallet service node 42 has a shared wallet service server
421 holding and communicating with user accounts. As the shared wallet service
node 42 is a node on the peer-to-peer cryptocurrency network it comprises the
5 elements needed for such a node, such as data directory 35, with the shared wallet
service server 421 having functions including that of the cryptocurrency client.
Figure 5 illustrates an embodiment of the disclosure where the
conventional transaction infrastructure of Figure 1 are augmented with elements of
the cryptocurrency infrastructure of Figures 3 and 4, using a new service model, to
10 enable effective use of cryptocurrency in a conventional transaction architecture.
In the arrangement shown, mobile phone 1 is used as a payment
management device as before, with payment card 2 as payment device. The digital
enablement service is not shown (but may in practice be present if mobile phone 1 is
also used as payment device). An exchange service 51 supporting transactions
15 according to an embodiment of the disclosure interacts with issuer 5 and also with the
payment management device and at least one peer-to-peer cryptocurrency exchange
52. In the arrangement shown, the user communicates not only with the exchange
service 51, but also with the cryptocurrency exchange 52. Exchange service 51 is
shown as a separate element in this arrangement, but may for example be a service
20 provided by the card issuer, in which case it may be provided as an element of the
issuer 5.
In embodiments of the disclosure, the payment device may be used to
transact with merchants using a conventional flat currency transaction system but
drawing on virtual currency resources. This increases enormously the options
25 available for the user in spending virtual currency. As will be discussed below, a
variety of options are possible using this overall approach. In some cases there may
be a transfer during the course of the transaction, and in others there may be an offline
transfer to restore an account balance to a predetermined value.
Figure 6 shows a structure of user accounts indicated at the location of
30 account provider. Issuer 5 provides a payment device account 61 used for
transactions using the conventional infrastructure. From the perspective of other
elements of the transaction infrastructure (in particular the terminal 4 and the
acquiring bank 6), this payment device account 61 operates consistently with any
other user account backed by an issuer 5 and transacts in one or more "flat"
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currencies. Exchange service 51 provides an exchange service account 62 used to
ensure that there is a currency balance available to be used by the payment device 2.
In embodiments, this may be integrated with the payment device account 61 (and may
thus be provided by the issuer 5) but here it is shown as a separate service. The user
5 also has a cryptocurrency account 63 with cryptocurrency exchange 52 ~ as shown
below, in embodiments the user allows access to the cryptocurrency account to the
exchange service 51 so that fimds may be drawn down from the cryptocurrency
account for use by the payment device 2.
Figure 7 shows an exemplary method of use of a payment device 2
10 according to an embodiment of the disclosure. Firstly, a user registers 710 with an
exchange such as cryptocurrency exchange 52 where his or her cryptocurrency is then
stored. It should be noted that this step~ and in general, embodiments of this
disclosure~ do not require use of cryptocurrency. This exchange may also be a way
for users to store flat currency, and may be useful where the flat currency is not
15 universally usable as a medium for transactions. The user also registers 720 with the
exchange service 51 and with the issuer 5 (as noted above, these may be the same
party) and receives a transaction device (such as transaction card 2) that can be used
to draw on cryptocurrency assets in the manner described below. Alternatively, the
user may already have a transaction card 2 from the issuer 5 and may be able to
20 expand their service offering to draw on cryptocurrency assets in this way by also
registering with the exchange service 51 and possibly also by empowering the
exchange service 51 to interact with the issuer 5 on the user's behalf in certain
situations set out below.
The user will then (for example, using the payment management
25 device) configure 730 his or her account with the exchange service 5 I to establish
suitable working parameters. These may include access details enabling the exchange
service 51 to represent the user at the cryptocurrency exchange so that the exchange
service 51 can draw down on the user's cryptocurrency balance and convert it to a flat
currency. Where the user has access to multiple cryptocurrency exchanges 52, the
30 user may also specify 740 which cryptocurrency exchange should be used to top up a
flat currency account (or may establish a preferred order, or other rules depending on
the nature of the transaction and the currency balances involved).
The user can also establish 750 a balance of flat currency to be held by
the exchange service 51 on behalf of the user ~ this balance of flat currency can then
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be left available for instant access for user transactions. To establish an initial
balance, the exchange service may then convert cryptocurrency as necessary using a
cryptocurrency exchange 52. A practical issue here is that conversion between
cryptocurrency and flat currency may be difficult to achieve during the normal time
5 period of a transaction using a conventional transaction infrastructure (up to a few
seconds). An off-the-chain cryptocurrency transaction is potentially of this speed, but
requires suitable resources to be available. An on-the-chain transaction, with
verification, is not this quick because of the need to verify the transaction through
embedding it in a block chain, which typically takes several minutes. The exchange
10 service 51 thus performs both a coordinating and a buffering role in enabling use of
cryptocurrency resources for transactions.
The user may then specifY 760 rules for topping up the account with
the exchange service 51. For example, the balance can then be topped up at a
predetermined point if it falls below a certain point (or it can simply be topped up
15 directly on any transaction). The top-up could be automatic and so under the control
of the exchange service, or if the user does not wish to release control to the exchange
service 51, the top-up could be a manual process with messages sent to the user to
advise when a top-up was required. If an automatic top-up is used, then the exchange
service 51 will initiate a buy order at the relevant exchange to top-up the user account.
20 Many models are possible within this structure for the user's account
with the issuer. In one model, the account could be used only for transactions from
the user's cryptocurrency reserves, in which case any transaction would contribute to
triggering the top-up process. In another model, the account could draw from both
c
flat currency and cryptocurrency sources, and appropriate rules could be determined
25 for drawing on the cryptocurrency reserves (for example, the account level falling
below a certain level, or falling below a certain level for a certain length oftime, or if
a monthly payment had not been made from any other source). The payment device
could be a prepaid card (in which case a positive balance would have to be maintained
for transactions to be authorised by the issuer) or a credit card, in which case
30 payments could be authorised until the negative balance on the account exceeded a
credit limit.
The steps in an exemplary transaction using this infrastructure are set
out below with reference to Figure 8. The payment device 2 is presented to the
terminal 4 and a transaction is initiated 810 in the conventional way. From the
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perspective of the terminal4 and the acquirer 9, the transaction will be entirely
conventional and will be conducted in an appropriate flat currency - the account with
the issuer will typically be in a specific flat currency as base currency, and while there
may the option typically allowed at a terminal to transact in the merchant's or the
5 user's base currency, it will not be relevant that the payment device ultimately draws
on cryptocurrency (or any other currency) reserves.
The transaction passes through the transaction infrastructure 7 to the
issuer 5 for authorisation 820. Authorisation will normally be made on the basis of a
number of factors, including authentication of the user and there being a sufficient
10 balance on the user account. While in embodiments it may be possible to involve the
exchange service 51 at the authorisation stage to ensure that there are sufficient user
funds available, this may not be generally desirable except perhaps where the
exchange service 51 is integrated with the issuer as otherwise authorisation will be
delayed- if authorisation is given then the transaction will complete in the normal
15 manner.
Depending on the rules established for use of the user issuer account,
there may then be a message sent 830 from the issuer to the exchange service to
advise on the transaction- this may take place after every transaction whether or not
account replenishment is required so that the exchange service can track user account
20 activity, or may only take place. when replenishment of the user issuer account is
required. When the exchange service determines 840 that issuer account
replenishment is required, it transfers flat currency accordingly and may, if the level
of flat currency that it holds will fall too low as a result, also determine that it needs to
'
convert cryptocurrency to replenish the exchange service account, the issuer account,
25 or both. The exchange service then places 850 a buy order for flat currency at the
relevant cryptocurrency exchange 52 as determined by its replenishment rules, or (if
top-ups are manual rather than automatic) advises the user what transaction is
required with which exchange. The currency is then bought (with any fees paid)
using the user's cryptocurrency reserves through the user's account with the
30 cryptocurrency exchange.
A variety oftop-up strategies may be used. A top-up may be triggered
only when the available balance falls to a certain level. Alternatively, a top-up may
be triggered after every transaction to maintain the account at the originally
established level- this will require more top-up activity, but will give the user greater
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assurance that the level of funds available will meet expectations.
As has been noted above, many variations are possible within this
overall structure. The exchange service 51 could in principle be merged with the
issuer 5 or with a cryptocurrency exchange 52 - in principle, all three functions could
5 be provided with one provider. Where there is consolidation of this kind, accounts in
the same currency (such as the user issuer account and the user flat currency account
with the exchange service) could in principle be consolidated together, obviating the
need for process steps that relate to interaction between the two. The user's
cryptocurrency reserves could in principle be held at the exchange service, at the
I 0 cryptocurrency exchanges, or elsewhere altogether, in which case there may be
additional steps required to transfer the cryptocurrency to the correct system element
with appropriate authorisation from the user.
As noted above, this approach is particularly effective to allow a user's
cryptocurrency reserves to be used through a conventional transaction infrastructure,
15 but it is not limited to this purpose. It may also be employed, for example, where a
user has reserves in any other currency (or indeed any other assets) that are
convertible into a flat currency but not at the speed required for normal transaction
flow in a conventional transaction infrastructure (or not reliably so). The skilled
person will appreciate that further modifications may be made to the approach set out
20 above in accordance with the spirit and scope of the disclosure.

CLAIMS
1. A computer-implemented service for converting digital assets into a
transaction currency for use by a payment device in a transaction system that is not
adapted for transactions using the digital assets, the service using a server with a
5 suitably programmed processor adapted to:
monitor a transaction currency balance in a user account associated with the
payment device, and to compare the transaction currency balance with rules for
maintaining the transaction currency balance; and
where required to do so by the rules, instructing conversion of user digital
10 assets at one or more exchanges into the transaction currency to maintain the
transaction currency balance.
2. The computer-implemented service as claimed in claim 1, wherein the
payment device is associated with an issuing bank, and wherein the computer-
IS implemented service is adapted to receive the transaction currency balance from the
issuing bank.
3. The computer-implemented service as claimed in claim 2, wherein the
computer-implementyd service is adapted to receive details oftransactions from the
20 user account in the transaction currency from the issuing bank or the transaction
system.
4. The computer-implemented service as claimed in any preceding claim,
wherein instructing conversion of digital assets into the transaction currency at the
25 one or more exchanges comprises instructing the one or more exchanges to make a
conversion transaction on behalf of an owner of the digital assets.
5. The computer-implemented service as claimed in any of claims 1 to 3,
wherein instructing conversion of digital assets into the transaction currency at the
30 one or more exchanges comprises advising an owner ofthe digital assets to make a
conversion transaction at the one or more exchanges.
6. The computer-implemented service of any preceding claim, wherein the
digital assets comprise cryptocurrency.
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5
7. A method of converting digital assets into a transaction currency for use in a
transaction system that is not adapted for transactions using the digital assets, the
method comprising:
storing digital assets for use with one or more exchanges adapted for
conversion of the digital assets into the transaction currency;
establishing a balance in the transaction currency for use by a payment device,
and establishing rules for maintaining the transaction currency balance; and
when required by the rules for maintaining the transaction currency balance,
10 instructing conversion of digital assets into the transaction currency at the one or more
exchanges for maintaining the transaction currency balance in the transaction
currency for use by the payment device.
8. The method of converting digital assets as claimed in claim 7, wherein the
15 digital assets comprise cryptocurrency assets.
20
25
30
9. The method of converting digital assets as claimed in claim 7 or claim 8,
wherein the rules comprise converting digital assets when the transaction currency
balance falls below a predetermined level.
10. The method of converting digital assets as claimed in claim 7 or claim 8,
wherein the rules comprise converting digital assets after a transaction in the
transaction currency to maintain the transaction currency balance at a predetermined
level.
11. The method of converting digital assets as claimed in any of claims 7 to 10,
wherein establishing the transaction currency balance comprises converting digital
assets to provide a predetermined transaction currency balance.
12. The method of converting digital assets as claimed in any of claims 7 to 1 0,
wherein instructing conversion of digital assets into the transaction currency at the
one or more exchanges comprises instructing the one or more exchanges to make a
conversion transaction on behalf of an owner ofthe digital assets.
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5
13. The method of converting digital assets as claimed in any of claims 7 to 12,
wherein instructing conversion of digital assets into the transaction currency at the
one or more exchanges comprises advising an owner of the digital assets to make a
conversion transaction at the one or more exchanges.