Note: Descriptions are shown in the official language in which they were submitted.
CA 02799734 2015-04-24
SECURE TEXT-TO-SPEECH SYNTHESIS IN PORTABLE ELECTRONIC DEVICES
FIELD OF THE INVENTION
[0001] The present disclosure relates generally to text-to-speech
synthesis. More
particularly, the present disclosure relates to a method and system for secure
text-to-speech
synthesis in portable electronic devices.
BACKGROUND OF THE INVENTION
[0002] Electronic devices, including portable electronic devices, have
gained
widespread use and may provide a variety of functions including, for example,
telephonic,
electronic messaging and other personal information manager (PIM) application
functions.
Portable electronic devices include, for example, several types of mobile
stations such as
simple cellular telephones, smart phones, wireless personal digital assistants
(PDAs), and
laptop computers with wireless 802.11 or Bluetooth TM capabilities.
[0003] Text-to-speech synthesis can be used in a number of
applications to convert
normal language text into speech, and can be implemented in software or
hardware. For
example, those who are visually impaired may use text-to-speech systems to
read textual
material. The use of text-to-speech synthesis can be useful in portable
electronic devices,
such as for the reading of email and text messages.
[0004] Improvements in devices using text-to-speech synthesis are
desirable.
BRIEF DESCRIPTION OF THE DRAWINGS
[0005] Embodiments of the present invention will now be described, by way
of
example only, with reference to the attached Figures, wherein:
[0006] Figure 1 is a block diagram of a portable electronic device in
accordance with
the disclosure.
[0007] Figure 2 is a block diagram of a host system of an example
configuration in
accordance with the disclosure.
[0008] Figure 3 is a flowchart of a method in accordance with the
disclosure.
[0009] Figure 4 is diagram of an example method of server-side
authentication in
accordance with the disclosure.
[0010] Figure 5 is diagram of an example method of server-side
authentication in
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accordance with the disclosure.
[0011] Figure 6 is diagram of an example method of device-side
authentication in
accordance with the disclosure.
DETAILED DESCRIPTION
[0012] The embodiments described herein generally relate to mobile wireless
communication devices, hereafter referred to as a portable electronic devices.
Examples of
applicable communication devices include pagers, cellular phones, cellular
smartphones,
wireless organizers, personal digital assistants, computers, laptops, tablets,
media players,
e- book readers, handheld wireless communication devices, wirelessly enabled
notebook
computers and the like. It will be appreciated that for simplicity and clarity
of illustration,
where considered appropriate, reference numerals may be repeated among the
figures to
indicate corresponding or analogous elements. In addition, numerous specific
details are set
forth in order to provide a thorough understanding of the embodiments
described herein.
However, it will be understood by those of ordinary skill in the art that the
embodiments
described herein may be practiced without these specific details. Also, the
description is not
to be considered as limiting the scope of the embodiments described herein.
[0013] Embodiments of the invention may be represented as a software,
or computer
program, product stored in a machine-readable medium (also referred to as a
computer-
readable medium, a processor-readable medium, or a computer-usable medium
having a
computer-readable program code embodied therein or stored thereon). The
machine-
readable medium may be any suitable medium, including magnetic, optical, or
electrical
storage medium including a diskette, compact disk read only memory (CD-ROM),
memory
device (volatile or non-volatile), or similar storage mechanism. The machine-
readable
medium may contain various sets of instructions, code sequences, configuration
information,
or other data, which, when executed, cause a processor, or processors, to
perform steps in a
method according to an embodiment of the invention. Those of ordinary skill in
the art will
appreciate that other instructions and operations necessary to implement the
described
invention may also be stored on the machine-readable medium. Software running
from the
machine readable medium may interface with circuitry or other hardware to
perform the
described tasks.
[0014] A portable electronic device may be a two-way communication
device with
advanced data communication capabilities, including the capability to
communicate with
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other portable electronic devices or computer systems through a network of
transceiver
stations. The portable electronic device may also have the capability to allow
voice
communication. Depending on the functionality provided by the portable
electronic device, it
may be referred to as a pager, cellular phone, cellular smartphone, wireless
organizer,
personal digital assistant, computer, laptop, tablet, media player, e- book
reader, handheld
wireless communication device, wirelessly-enabled notebook computer and the
like. To aid
the reader in understanding the structure of the portable electronic device
and how it
communicates with other devices and host systems, reference will now be made
to Figures 1
through 4.
[0015] Referring first to Figure 1, shown therein is a block diagram of a
portable
electronic device 100. The portable electronic device 100 includes a number of
components
such as a main processor 102 that controls the overall operation of the
portable electronic
device 100. Communication functions, including data and voice communications,
are
performed through a communication subsystem 104. Data received by the portable
electronic device 100 can be optionally decompressed and decrypted by decoder
103,
operating according to any suitable decompression techniques (e.g. using
decompression
techniques for MPEG, JPEG, ZIP compression techniques) and decryption
techniques (e.g.
using decryption techniques for Data Encryption Standard (DES), Triple DES, or
Advanced
Encryption Standard (AES) encryptior techniques). The communication subsystem
104
receives messages from and sends messages to a wireless network 200. In this
example
embodiment of the portable electronic device 100, the communication subsystem
104 can be
configured in accordance with the Global System for Mobile Communication (GSM)
and
General Packet Radio Services (GPRS) standards, Enhanced Data GSM Environment
(EDGE), Universal Mobile Telecommunications Service (UMTS), or the like. New
standards
are still being defined, but it is believed that they will have similarities
to the network behavior
described herein, and it will also be understood by persons skilled in the art
that the
embodiments described herein are intended to use any other suitable standards
that are
developed in the future. The wireless link connecting the communication
subsystem 104 with
the wireless network 200 represents one or more different Radio Frequency (RF)
channels,
operating according to defined protocols specified for GSM/GPRS
communications. With
newer network protocols, these channels are capable of supporting both circuit
switched
voice communications and packet switched data communications.
[0016] Although the wireless network 200 associated with portable
electronic device
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100 is a GSM/GPRS wireless network in one example implementation, other
wireless
networks may also be associated with the portable electronic device 100 in
variant
implementations. The different types of wireless networks that may be employed
include, for
example, data-centric wireless networks, voice-centric wireless networks, and
dual-mode
networks that can support both voice and data communications over the same
physical base
stations. Combined dual-mode networks include, but are not limited to, Code
Division
Multiple Access (CDMA) or CDMA2000 networks, GSM/GPRS networks, and third-
generation (30) and fourth-generation (4G) networks, such as EDGE, UMTS, High-
Speed
Downlink Packet Access (HSDPA), Worldwide Interoperability for Microwave
Access
(WiMAX), Long Term Evolution (LTE), and LTE Advanced. Some other examples of
data-
centric networks include WiFi 802.11, Mobitex TM and DataTACTm network
communication
systems. Examples of other voice-centric data networks include Personal
Communication
Systems (PCS) networks like GSM and Time Division Multiple Access (TDMA)
systems. The
main processor 102 can also interact with additional subsystems such as a
Random Access
Memory (RAM) 106, a flash memory 108, a display 110, an auxiliary input/output
(I/0)
subsystem 112, a data port 114, a keyboard 116, a speaker 118, a microphone
120, short-
range communications 122 and other device subsystems 124.
[0017] Some of the subsystems of the portable electronic device 100
perform
communication-related functions, whereas other subsystems may provide
"resident" or on-
device functions. By way of example, the display 110 and the keyboard 116 may
be used for
both communication-related functions, such as entering a text message for
transmission over
the network 200, and device-resident functions such as a calculator or task
list.
[0018] The portable electronic device 100 can send and receive
communication
signals over the wireless network 200 after required network registration or
activation
procedures have been completed. Network access is associated with a subscriber
or user of
the portable electronic device 100. To identify a subscriber, the portable
electronic device
100 can, for example, use a SIM/RUIM card 126 (i.e. Subscriber Identity Module
or a
Removable User Identity Module) inserted into a SIM/RUIM interface 128 in
order to
communicate with a network. A SIM is typically a component of a SIM card that
can be
inserted into a mobile device in order to associate that device with the user
identified by the
SIM. SIM cards can have various form factors such as a full size that is
approximately the
size of a credit card, a smaller mini size, and a still smaller micro size.
Other cards, such as
the Universal Integrated Circuit Card (UICC), the Universal Subscriber
Identity Module
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(USIM) card, or the Removable User identity Module (R-UIM) card, may function
in a similar
manner. Alternatively, a SIM could be stored on an embedded UICC (eUICC) or a
similar
software-based SIM module. Any such card or software module will be referred
to herein as
a SIM card, but it should be understood that such entities do not necessarily
have the form
factor of a card. Without the SIM card 126, the portable electronic device 100
is not fully
operational for communication with the wireless network 200. By inserting the
SIM
card/RUIM 126 into the S1M/RUIM interface 128, a subscriber can access all
subscribed
services. Services may include: web browsing and messaging such as e-mail,
voice mail,
Short Message Service (SMS), and Multimedia Messaging Services (MMS). More
advanced
services may include: point of sale, field service and sales force automation.
The SIM
card/RUIM 126 includes a processor and memory for storing information. Once
the SIM
card/RUIM 126 is inserted into the SIM/RUIM interface 128, it is coupled to
the main
processor 102. In order to identify the subscriber, the SIM card/RUIM 126 can
include some
user parameters such as an International Mobile Subscriber Identity (IMSI). An
advantage of
using the SIM card/RUIM 126 is that a subscriber is not necessarily bound by
any single
physical portable electronic device. The SIM card/RUIM 126 may store
additional subscriber
information for a portable electronic device as well, including datebook (or
calendar)
information and recent call information. Alternatively, user identification
information can also
be programmed into the flash memory 108.
[0019] The portable electronic device 100 is a battery-powered device and
includes a
battery interface 132 for receiving one, or more rechargeable batteries 130.
In at least some
embodiments, the battery 130 can be a smart battery with an embedded
microprocessor.
The battery interface 132 is coupled to a regulator (not shown), which assists
the battery 130
in providing power V+ to the portable electronic device 100. Although current
technology
makes use of a battery, future technologies such as micro fuel cells may
provide the power
to the portable electronic device 100.
[0020] The portable electronic device 100 also includes an operating
system 134 and
software components 136, which are described in more detail below. The
operating system
134 and the software components 136 that are executed by the main processor
102 are
typically stored in a persistent store such as the flash memory 108, which may
alternatively
be a read-only memory (ROM) or similar storage element (not shown). Those
skilled in the
art will appreciate that portions of the operating system 134 and the software
components
136, such as specific device applications, or parts thereof, may be
temporarily loaded into a
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volatile store such as the RAM 106. Other software components can also be
included, as is
well known to those skilled in the art.
[0021] The subset of software applications 136 that control basic
device operations,
including data and voice communication applications, will normally be
installed on the
portable electronic device 100 during its manufacture. Other software
applications include a
message application 138 that can be any suitable software program that allows
a user of the
portable electronic device 100 to send and receive electronic messages.
Various alternatives
exist for the message application 138 as is well known to those skilled in the
art. Messages
that have been sent or received by the user are typically stored in the flash
memory 108 of
the portable electronic device 100 or some other suitable storage element in
the portable
electronic device 100. In at least some embodiments, some of the sent and
received
messages may be stored remotely from the device 100 such as in a data store of
an
associated host system with which the portable electronic device 100
communicates.
[0022] The software applications can further include a device state
module 140, a
Personal Information Manager (PIM) 142, and other suitable modules (not
shown). The
device state module 140 provides persistence, i.e. the device state module 140
ensures that
important device data is stored in persistent memory, such as the flash memory
108, so that
the data is not lost when the portable electronic device 100 is turned off or
loses power.
[0023] The PIM 142 includes functionality for organizing and managing
data items of
interest to the user, such as, but not limited to, e-mail, contacts, calendar
events, voice mails,
appointments, and task items. A PIM application has the ability to send and
receive data
items via the wireless network 200. PIM data items may be seamlessly
integrated,
synchronized, and updated via the wireless network 200 with the portable
electronic device
subscriber's corresponding data items stored and/or associated with a host
computer
system. This functionality creates a mirrored host computer on the portable
electronic device
100 with respect to such items. This can be particularly advantageous when the
host
computer system is the portable electronic device subscriber's office computer
system.
[0024] The portable electronic device 100 also includes a connect
module 144, and
an information technology (IT) policy module 146. The connect module 144
implements the
communication protocols that are required for the portable electronic device
100 to
communicate with the wireless infrastructure and any host system, such as an
enterprise
system, with which the portable electronic device 100 is authorized to
interface. Examples of
a wireless infrastructure and an enterprise system are given in Figures 3 and
4, which are
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described in more detail below.
[0025] The connect module 144 includes a set of APIs that can be
integrated with the
portable electronic device 100 to allovv the portable electronic device 100 to
use any number
of services associated with the enterprise system. The connect module 144
allows the
portable electronic device 100 to establish an end-to-end secure,
authenticated
communication pipe with the host system. A subset of applications for which
access is
provided by the connect module 144 can be used to pass IT policy commands from
the host
system to the portable electronic device 100. This can be done in a wireless
or wired
manner. These instructions can then be passed to the IT policy module 146 to
modify the
configuration of the device 100. Alternatively, in some cases, the IT policy
update can also
be done over a wired connection.
[0026] Other types of software applications can also be installed on
the portable
electronic device 100. These software applications can be third party
applications, which are
added after the manufacture of the portable electronic device 100. Examples of
third party
applications include games, calculators, utilities, etc.
[0027] The additional applications can be loaded onto the portable
electronic device
100 through at least one of the wireless network 200, the auxiliary I/0
subsystem 112, the
data port 114, the short-range communications subsystem 122, or any other
suitable device
subsystem 124. This flexibility in application installation increases the
functionality of the
portable electronic device 100 and may provide enhanced on-device functions,
communication-related functions, or both. For example, secure communication
applications
may enable electronic commerce functions and other such financial transactions
to be
performed using the portable electronic device 100.
[0028] The data port 114 enables a subscriber to set preferences
through an external
device or software application and extends the capabilities of the portable
electronic device
100 by providing for information or software downloads to the portable
electronic device 100
other than through a wireless communication network. The alternate download
path may, for
example, be used to load an encryption key onto the portable electronic device
100 through
a direct and thus reliable and trusted connection to provide secure device
communication.
The data port 114 can be any suitable port that enables data communication
between the
portable electronic device 100 and another computing device. The data port 114
can be a
serial or a parallel port. In some instances, the data port 114 can be a USB
port that includes
data lines for data transfer and a supply line that can provide a charging
current to charge
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the battery 130 of the portable electronic device 100.
[0029] The short-range communications subsystem 122 provides for
communication
between the portable electronic device 100 and different systems or devices,
without the use
of the wireless network 200. For exari- ple, the subsystem 122 may include an
infrared device
and associated circuits and components for short-range communication. Examples
of short-
range communication standards include standards developed by the Infrared Data
Association (IrDA), Bluetooth TM, Near Field Communication (NFC) standards,
and the 802.11
family of standards developed by IEEE.
[0030] In use, a received signal such as a text message, an e-mail
message, or web
page download will be processed by the communication subsystem 104 and input
to the
main processor 102. The main processor 102, in conjunction with the decoder
103, will then
process the received signal for output to the display 110 or alternatively to
the auxiliary I/0
subsystem 112. A subscriber may also compose data items, such as e-mail
messages, for
example, using the keyboard 116 in conjunction with the display 110 and
possibly the
auxiliary 1/0 subsystem 112. The auxiliary subsystem 112 may include devices
such as: a
touch screen, mouse, track ball, trackpad, optical joystick, infrared
fingerprint detector, or a
roller wheel with dynamic button pressing capability. The keyboard 116 can
include an
alphanumeric keyboard and/or telephone-type keypad. However, other types of
keyboards,
including a virtual keyboard or an external keyboard, may also be used. A
composed item
may be transmitted over the wireless network 200 through the communication
subsystem
104.
[0031] For voice communications, the overall operation of the portable
electronic
device 100 may be substantially similar, except that the received signals are
output to the
speaker 118, and signals for transmission are generated by the microphone 120.
Alternative
voice or audio I/0 subsystems, such as a voice message recording subsystem,
can also be
implemented on the portable electronic device 100. Although voice or audio
signal output is
accomplished primarily through the speaker 118, the display 110 can also be
used to provide
additional information such as the identity of a calling party, duration of a
voice call, or other
voice call related information.
[0032] Figure 2 is a block diagram illustrating components of a
configuration of a host
system 250 with which the portable electronic device 100 can, in conjunction
with the
connect module 144, communicate. The host system 250 will typically be a
corporate
enterprise or other local area network (LAN), but may also be a home office
computer or
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some other private system, for example, in variant implementations. In this
example shown in
Figure 4, the host system 250 is depicted as a LAN of an organization to which
a user of the
portable electronic device 100 belongs. Typically, a plurality of portable
electronic devices
can communicate wirelessly with the host system 250 through one or more nodes
202 of the
wireless network 200.
[00331 The host system 250 includes a number of network components
connected to
each other by a network 260. For instance, a user's desktop computer 262a is
situated on a
LAN connection. The portable electronic device 100 can be directly coupled to
the computer
262a by a serial or a Universal Serial Bus (USB) connection, for example, or
can be
wirelessly connected, such as through a Bluetooth TM connection. The
connection of the
portable electronic device 100 to the computer facilitates the loading of
information (e.g. PIM
data, private symmetric encryption keys to facilitate secure communications)
from the user
computer 262a to the portable electronic device 100, and may be particularly
useful for bulk
information updates often performed in initializing the portable electronic
device 100 for use.
The information downloaded to the portable electronic device 100 may include
digital
certificates used in the exchange of messages.
[0034] The user computers 262a-262n will typically also be connected
to other
peripheral devices, such as printers, etc. which are not explicitly shown in
Figure 4.
Furthermore, only a subset of network components of the host system 250 are
shown in
Figure 4 for ease of exposition, and it will be understood that the host
system 250 will include
additional components that are not explicitly shown in Figure 4 for this
example configuration.
More generally, the host system 250 may represent a smaller part of a larger
network (not
shown) of the organization, and may include different components and/or be
arranged in
different topologies than that shown in the example embodiment of Figure 4.
[0035] To facilitate the operati'on of the portable electronic device 100
and the
wireless communication of messages and message-related data between the
portable
electronic device 100 and components of the host system 250, a number of
wireless
communication support components 270 can be provided. In some implementations,
the
wireless communication support components 270 can include a message management
server 272, a mobile data server (MDS) 274, a web server, such as Hypertext
Transfer
Protocol (HTTP) server 275, a contact server 276, and a device manager module
278. HTTP
servers can also be located outside the enterprise system, as indicated by the
HTTP server
275 attached to the network 224. The device manager module 278 includes an IT
Policy
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editor 280 and an IT user property editor 282, as well as other software
components for
allowing an IT administrator to configure the portable electronic devices 100.
In an alternative
embodiment, there may be one editor that provides the functionality of both
the IT policy
editor 280 and the IT user property editor 282. The support components 270
also include a
data store 284, and an IT policy server 286. The IT policy server 286 includes
a processor
288, a network interface 290 and a memory unit 292. The processor 288 controls
the
operation of the IT policy server 286 and executes functions related to the
standardized IT
policy as described below. The network interface 290 allows the IT policy
server 286 to
communicate with the various components of the host system 250 and the
portable
electronic devices 100. The memory unit 292 can store functions used in
implementing the IT
policy as well as related data. Those skilled in the art know how to implement
these various
components. Other components may also be included as is well known to those
skilled in the
art. Further, in some implementations, the data store 284 can be part of any
one of the
servers.
[00361 In this example embodiment, the portable electronic device 100
communicates with the host system 250 through node 202 of the wireless network
200 and a
shared network infrastructure 224 such as a service provider network or the
public Internet.
Access to the host system 250 may be provided through one or more routers (not
shown),
and computing devices of the host system 250 may operate from behind a
firewall or proxy
server 266. The proxy server 266 provides a secure node and a wireless
internet gateway for
the host system 250. The proxy server 266 intelligently routes data to the
correct destination
server within the host system 250.
[0037] In some implementations, the host system 250 can include a
wireless VPN
router (not shown) to facilitate data exchange between the host system 250 and
the portable
electronic device 100. The wireless VPN router allows a VPN connection to be
established
directly through a specific wireless neiwork to the portable electronic device
100. The
wireless VPN router can be used with the Internet Protocol (IP) Version 6
(IPV6) and IP-
based wireless networks. This protocol can provide enough IP addresses so that
each
portable electronic device has a dedicated IP address, making it possible to
push information
to a portable electronic device at any time. An advantage of using a wireless
VPN router is
that it can be an off-the-shelf VPN component, and does not require a separate
wireless
gateway and separate wireless infrastructure. A VPN connection can be a
Transmission
Control Protocol (TCP)/1P or User Datagram Protocol (UDP)/1P connection for
delivering the
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messages directly to the portable electronic device 100 in this alternative
implementation.
[0038] Messages intended for a user of the portable electronic device
100 are initially
received by a message server 268 of the host system 250. Such messages may
originate
from any number of sources. For instance, a message may have been sent by a
sender from
the computer 262b within the host system 250, from a different portable
electronic device
(not shown) connected to the wireless network 200 or a different wireless
network, or from a
different computing device, or other dnvice capable of sending messages, via
the shared
network infrastructure 224, possibly through an application service provider
(ASP) or Internet
service provider (ISP), for example.
[0039] The message server 268 typically acts as the primary interface for
the
exchange of messages, particularly e-mail messages, within the organization
and over the
shared network infrastructure 224. Each user in the organization that has been
set up to
send and receive messages is typically associated with a user account managed
by the
message server 268. Some example implementations of the message server 268
include a
Microsoft ExchangeTM server, a Lotus Domino Tmserver, a Novell
GroupwiseTmserver, or
another suitable mail server installed in a corporate environment. In some
implementations,
the host system 250 may include multiple message servers 268. The message
server 268
may also be adapted to provide additional functions beyond message management,
including the management of data associated with calendars and task lists, for
example.
[0040] When messages are received by the message server 268, they are
typically
stored in a data store associated with the message server 268. In at least
some
embodiments, the data store may be a separate hardware unit, such as data
store 284, with
which the message server 268 communicates. Messages can be subsequently
retrieved and
delivered to users by accessing the message server 268. For instance, an e-
mail client
application operating on a user's computer 262a may request the e-mail
messages
associated with that user's account stored on the data store associated with
the message
server 268. These messages are thei. retrieved from the data store and stored
locally on the
computer 262a. The data store associated with the message server 268 can store
copies of
each message that is locally stored on the portable electronic device 100.
Alternatively, the
data store associated with the message server 268 can store all of the
messages for the user
of the portable electronic device 100 and only a smaller number of messages
can be stored
on the portable electronic device 100 to conserve memory. For instance, the
most recent
messages (i.e. those received in the past two to three months for example) can
be stored on
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the portable electronic device 100.
[0041] When operating the portable electronic device 100, the user may
wish to have
e-mail messages retrieved for delivery to the portable electronic device 100.
The message
application 138 (see Figure 1) operating on the portable electronic device 100
may also
request messages associated with the user's account from the message server
268. The
message application 138 may be configured (either by the user or by an
administrator,
possibly in accordance with an organization's IT policy) to make this request
at the direction
of the user, at some pre-defined time :nterval, or upon the occurrence of some
pre-defined
event. In some implementations, the portable electronic device 100 is assigned
its own e-
1 0 mail address, and messages addressed specifically to the portable
electronic device 100 are
automatically redirected to the portable electronic device 100 as they are
received by the
message server 268.
[0042] The message management server 272 can be used to specifically
provide
support for the management of messages, such as e-mail messages, that are to
be handled
by portable electronic devices. Generally, while messages are still stored on
the message
server 268, the message management server 272 can be used to control when, if,
and how
messages are sent to the portable electronic device 100. The message
management server
272 also facilitates the handling of messages composed on the portable
electronic device
100, which are sent to the message server 268 for subsequent delivery.
[0043] For example, the message management server 272 may monitor the
user's
"mailbox" (e.g. the message store associated with the user's account on the
message server
268) for new e-mail messages, and apply user-definable filters to new messages
to
determine if and how the messages are relayed to the user's portable
electronic device 100.
The message management server 272 may also, through an encoder 273, compress
messages, using any suitable compression technology (e.g. using a compression
technique
such as ZIP, MPEG, JPEG and other known techniques) and encrypt messages (e.g.
using
an encryption technique such as Data Encryption Standard (DES), Triple DES, or
Advanced
Encryption Standard (AES)), and pusl: them to the portable electronic device
100 via the
shared network infrastructure 224 and the wireless network 200. The message
management
server 272 may also receive messages composed on the portable electronic
device 100 (e.g.
encrypted using Triple DES), decrypt and decompress the composed messages, re-
format
the composed messages if desired so that they will appear to have originated
from the user's
computer 262a, and re-route the composed messages to the message server 268
for
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delivery.
[0044] Certain properties or restrictions associated with messages
that are to be sent
from and/or received by the portable electronic device 100 can be defined
(e.g. by an
administrator in accordance with IT policy) and enforced by the message
management
server 272. These may include whether the portable electronic device 100 may
receive
encrypted and/or signed messages, minimum encryption key sizes, whether
outgoing
messages must be encrypted and/or signed, and whether copies of all secure
messages
sent from the portable electronic device 100 are to be sent to a pre-defined
copy address, for
example.
[0045] The message management server 272 may also be adapted to provide
other
control functions, such as only pushing certain message information or pre-
defined portions
(e.g. "blocks") of a message stored on the message server 268 to the portable
electronic
device 100. For example, in some cases, when a message is initially retrieved
by the
portable electronic device 100 from the message server 268, the message
management
server 272 may push only the first part of a message to the portable
electronic device 100,
with the part being of a pre-defined size (e.g. 2 KB). The user can then
request that more of
the message be delivered in similar-sized blocks by the message management
server 272 to
the portable electronic device 100, possibly up to a maximum pre-defined
message size.
Accordingly, the message management server 272 facilitates better control over
the type of
data and the amount of data that is communicated to the portable electronic
device 100, and
can help to minimize potential waste of bandwidth or other resources.
[0046] The MDS 274 encompasses any other server that stores
information that is
relevant to the corporation. The mobile data server 274 may include, but is
not limited to,
databases, online data document repositories, customer relationship management
(CRM)
systems, or enterprise resource planning (ERP) applications. The MDS 274 can
also connect
to the Internet or other public network, through HTTP server 275 or other
suitable web server
such as an File Transfer Protocol (FTP) server, to retrieve HTTP webpages and
other data.
Requests for webpages are typically routed through MDS 274 and then to HTTP
server 275,
through suitable firewalls and other protective mechanisms. The web server
then retrieves
the webpage over the Internet, and returns it to MDS 274. As described above
in relation to
message management server 272, MDS 274 is typically provided, or associated,
with an
encoder 277 that permits retrieved data, such as retrieved webpages, to be
compressed,
using any suitable compression technology, and encrypted, using an suitable
encryption
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technique, as described above, and then pushed to the portable electronic
device 100 via the
shared network infrastructure 224 and the wireless network 200.
[0047] The contact server 276 can provide information for a list of
contacts for the
user in a similar fashion as the address book on the portable electronic
device 100.
Accordingly, for a given contact, the contact server 276 can include the name,
phone
number, work address and e-mail address of the contact, among other
information. The
contact server 276 can also provide a global address list that contains the
contact
information for all of the contacts associated with the host system 250.
[0048] It will be understood by persons skilled in the art that the
message
management server 272, the MDS 274, the HTTP server 275, the contact server
276, the
device manager module 278, the data store 284 and the IT policy server 286 do
not need to
be implemented on separate physical servers within the host system 250. For
example,
some or all of the functions associated with the message management server 272
may be
integrated with the message server 268, or some other server in the host
system 250.
Alternatively, the host system 250 may include multiple message management
servers 272,
particularly in variant implementations where a large number of portable
electronic devices
need to be supported.
[0049] The present disclosure describes a method for secure text-to-
speech
conversion of text using speech or voice synthesis. Voice synthesis of text-
based content
can be used to synthesize any text-based content to an audio format for output
to a recipient.
For example, in a car environment it is may be undesirable for a driver to
read an email or
text message, and the use of text-to-speech synthesis can be used. However,
the voice used
in various text-to-speech systems is either a machine-generated voice, or a
voice provided
by a voice actor, not the sender, both of which can sound unnatural.
Therefore, it is desirable
to provide text-to-speech synthesis that permits messages to be read in a
natural manner, for
example in the voice of the sender, or another voice that is familiar to the
recipient. However,
to prevent the originator's voice from being used or distributed
inappropriately or in an
unauthorized manner, appropriate security and access controls need to be
provided. For
example, when voice synthesis is used to read an email message, it is
desirable to have
appropriate controls to ensure that th message is read in the originator's
voice, not the
voice of another person. Such controls permit an originator's voiceprint file
to be publicly
accessible, but limit its use for voice synthesis to text-based content
created by the
originator, or sent to a trusted recipient. In this way a person can be
assured that their voice
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CA 02799734 2015-04-24
cannot be used for content they did not write.
[0050] Referring to Figure 3, the method generally consists of
authenticating at least
one of an originator or a recipient of text-based content to access a
voiceprint associated
with the text-based content (302), and converting at least a portion of the
text-based content
to an audio format for output to the recipient in accordance with the
originator's voiceprint
(304). As used herein, "text-based content" encompasses any digital text
content that can be
synthesized for audio read out to the recipient. Examples of text-based
content includes, but
is not limited to, email messages, text messages, attachments to messages,
calendar
appointments, tasks, and text portions of any thereof. The "originator" of the
text-based
content is the creator of the digital content, who, in many of the described
embodiments, is
the sender of a message, such as the.sender of an email message. However,
there are
embodiments where the text-based content originates from another source, such
as the
creator of an attachment who is different from the sender of the message, or
the creator of a
calendar appointment or task, who may be, for example, the user of a portable
electronic
device (recipient) him or herself.
[0051] The present disclosure is not limited to a particular method
of voice synthesis,
and any known or later developed voice synthesis method can be used. As an
example,
voice synthesis based on hidden Markov models (HMM) is one method that can be
used.
HMM (also called Statistical Parametric Synthesis) models the frequency
spectrum (vocal
tract), fundamental frequency (vocal source), and duration (prosody) of a
person's speech to
generate hidden Markov models (sequence model and observation model), which
are
collectively termed herein a "voiceprint" of a speaker, sender or originator.
The voiceprint can
be stored as a voiceprint file. Speech waveforms can then be generated from
the voiceprint.
Advantages of HMM-based voice synthesis include the relatively short training
time (e.g. <
approximately 2 hours) needed to generate a voiceprint, and small size (e.g.
typically less
than approximately 5MB) of the resulting voiceprint file. The small size of
the voiceprint files
reduces the bandwidth needed to transmit such files, and the memory needed to
store them.
In contrast, other natural voice synthesis techniques can require many hours
of training, and
generate voiceprint files of 11MB to 1GB in size. A voiceprint can also, for
example, be an
adaptive voiceprint that adapts a "common" voice to a specific speaker.
[0052] Referring to Figures 1 and 2, the method can be accomplished
at a server,
such as the message management server 272 (see Figure 2), or on a portable
electronic
device, or on a combination thereof. For example, a server to provide secure
text-to-speech
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CA 02799734 2015-04-24
conversion of text-based content can include a processor capable of
authenticating at least
one of an originator or a recipient of the text-based content, accessing a
voiceprint
associated with the originator of the text-based content; and converting, in
accordance with
the voiceprint, at least a portion of the text-based content to an audio
format for output to the
recipient or listener. A portable electronic device to provide secure text-to-
speech conversion
of text-based content according to the present disclosure can include a
processor, such as
main processor 102 (see Figure 1), configured to authenticate an originator of
the text-based
content; access a voiceprint associated with the originator; convert at least
a portion of the
text-based content to an audio format in accordance with the voiceprint; and
cause the audio
format to be output to an audio output device of the portable device, such as
speaker 118
(see Figure 1) or another associated sound output device, such as a speaker
paired to a
portable electronic device through Bliietooth TM, such as a BluetoothTM car
set, or a headset.
[0053] A number of methods can be used to provide the security or
authentication
controls at the server-side or the device-side. According to embodiments,
authentication of at
least one of the originator or the recipient can include verifying a digital
signature of at least
one of the originator or the recipient, or authenticating the originator in
accordance with a
digital certificate accompanying the text-based content. Authenticating at
least one of the
originator or the recipient can further include verifying that the recipient
is a trusted recipient.
[0054] Server-side authentication permits a trusted third party, such
as a wireless
service provider or an enterprise to authenticate the originator and/or the
recipient, and
securely perform conversion of the text-based content to an audio format. For
the purposes
of illustration in the following example embodiments, the text-based content
is an email
message. The following examples assume that the originator of the text-based
content has
created a voiceprint, using HMM or other appropriate method, prior to creating
or transmitting
text-based content.
[0055] In a first embodiment, as shown in Figure 4, the originator of
the message is
authenticated by a trusted server 400 using a certificate-based
authentication. The voiceprint
file (HMM VP) is uploaded by the originator (A) to the server 400 of a trusted
third party with
a digital certificate (Cert A) (402). This step can occur at any time prior
to, or
contemporaneously with, the creation or transmission of the text-based
content, and the
communication may be secured using known or later developed methods, such as
Secure
Sockets Layer (SSL). A digital certificate (also known as a public key
certificate or identity
certificate) generally refers to an electronic document which uses a digital
signature to bind a
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CA 02799734 2015-04-24
public key with an identity - information such as the name of a person or an
organization,
their address, etc. The certificate can be used to verify that a public key
belongs to an
individual. A valid digital signature gives a recipient reason to believe that
the message was
created by a known sender, and that it was not altered in transit. While the
present
embodiment will be described using digital certificates, the authentication
method can be
easily adapted, using shared symmetric keys, or to use messages simply signed
with a
digital signature.
[0056] User A then sends a message to B, over any appropriate
communication
channel, and signs the message with the private key that corresponds to Cert
A. An email
client, such as provided by message application 138 (see Figure 1), on a
portable electronic
device associated with B, receives the signed message (404). The email client
then forwards
the email message and signature to the trusted server 400 (406), for example,
over a secure
connection, such as an Secure Sockets Layer (SSL) or a Transport Layer
Security (TLS)
connection. The forwarding of the message and signature to the server 400 can
be
performed automatically by the email client on receipt of a signed message;
can be user-
initiated; can be based on specified conditions, such as time of day, presence
status of user
B; or can be based on user-specified preferences. In accordance with an
embodiment, only a
portion of a message is signed with A's digital signature, and only the signed
portion is
forwarded and converted to speech. This embodiment is particularly appropriate
for large text
messages, such as long email threads, where it is only desirable to convert
the newly added
portion of the thread into speech.
[0057] On receipt of the message, the server 400 verifies the
signature (408), thereby
verifying the identity of sender A. If the signature verifies correctly, the
server 400 then
verifies the status of the certificate to ensure it has not expired or been
revoked (410). The
server 400 then retrieves the voiceprint file (HMM VP) associated with the
certificate (412),
converts the email message to an audio format (414) and transfers the audio
message back
to B's device to play (416).
[0058] Alternately, as shown by the dotted path 407, the message can
be
automatically intercepted by a server prior to receipt by the email client.
The intercepting
server can be, for example, the enterprise server 270 (see Figure 2), which
may also be the
trusted server. Alternately, the intercepting server may forward the
intercepted message to
the trusted server. The conditions for such interception can also be based on
specified
conditions, such as time of day, presence status of user B; or can be based on
user-specified
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CA 02799734 2015-04-24
preferences. The originator A is authenticated at the trusted server, as
described above, and
the trusted server then sends the audio message directly to the device, or
back to the
enterprise server which then pushes the result to the device. This embodiment
avoids having
the email client of the device have to send the message, which may be quite
large if
attachments are included, to the trusted server.
[0059] In the embodiment shown in Figure 5, the recipient of the
message is
authenticated by a trusted server 500 and compared to a list of trusted
recipients provided by
sender A. In this way, A can grant permissions to certain trusted parties to
be able to play
messages using his voiceprint. In this embodiment, A's voiceprint file (HMM
VP) is
transmitted, over a secure connection, to a server 500, with a list of trusted
recipients (502).
When A causes a text message to be sent to B (504), the email client at B
signs the
message with B's signature, and forwards the signed email message to the
trusted server
500 (506), as described above. On receipt of the message, the server 500
verifies B's
signature (508), thereby verifying the identity of the recipient B. If B's
signature verifies
correctly, the server 500 then verifies that B is included in the list of
trusted recipients
previously provided by A (510). If B is on the list of trusted recipients,
server 500 retrieves
A's voiceprint file (HMM VP) (512), converts the email message to an audio
format (514) and
transfers the audio message back to B's device (516).
[0060] A further embodiment (not shown), authenticates both A and B
by combining
the authentication methods shown in Figures 4 and 5. In other words, the
server verifies the
identity of B as well as verifying that the content is from A. Sender A's
voiceprint, digital
certificate and a list of trusted recipients are transmitted to the server. A
causes a digitally
signed message to be sent to B, the signed message is, in turn, signed by the
email client of
B and forwarded to the server. The server then authenticates B based on B's
signature and
the list of trusted recipients, and authenticates A based on A's signature and
the status of A's
certificate. If both A and B are authenticated, A's voiceprint is retrieved,
and the message
converted as set out above.
[0061] According to further embodiments, device-side authentication
can be
implemented using digital rights management (DRM) techniques. In an example
device-side
solution, the voiceprint file is stored in an encrypted format, and only
decrypted if the identity
of A and/or B is verified. Referring to Figure 6, originator uploads the
voiceprint file (HMM
VP) to a server 600, with a list of trusted recipients, or other permissions
(602). The server
encrypts the file (604). The email client of the device associated with B then
requests the
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encrypted voiceprint file for A from a server 600, such as a Lightweight
Directory Access
Protocol (LDAP) server (606). If A has set permissions as to who can retrieve
the voiceprint
file, the server 600 can verify the identity of B (608). The server and B's
device then establish
a key to use to encrypt the content (610), using, for example, the Simple
Password
Exponential Key Exchange (SPEKE), or Public Key Infrastructure (PKI)
techniques. The
encrypted file is transmitted to B (612). When the file is received by B, it
can either be directly
stored encrypted or re-encrypted with a different key which is stored in a
protected manner
within the hardware of the device. In accordance with various embodiments, the
encrypted
voice print file/decryption key is only accessible to the email client, which
can be enforced
using, for example, code signing on the email client application. When the
email client of B
receives a digitally signed email message (614) from A (for which it has a
stored voiceprint
file), the email client verifies the email signature (616), temporarily
decrypts the voiceprint file
(618), and convert the email to audio format (620).
[0062] The encrypted voiceprint file can optionally have an attached
digital certificate
to permit B to verify that the source of.,the signed message is A, as
described above in
relation to Figure 4. Any suitable techniques, such as those supported by
S/MIME
(Secure/Multipurpose Internet Mail Extensions), can be used in the exchange of
certificates.
The certificate permits the verification of trust status, revocation status
and expiry on the
message, and only if all conditions are valid is the voiceprint file
temporarily decrypted. For
example, using a certificate permits A to revoke the certificate at any time,
thereby easily
disallowing future text-to-speech conversions. Other methods are also
contemplated to
permit the originator to set more fine grained control over the use of the
voiceprint file. For
example, the trusted server and recipient devices could store and enforce
rules permitting
conversion of only a limited number of words of a message, or limit conversion
to a particular
time date or time range.
[0063] The above-described embodiments of the present invention are
intended to be
examples only. Alterations, modifications and variations may be effected to
the particular
embodiments by those of skill in the art without departing from the scope of
the invention,
which is defined solely by the claims appended hereto.
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