WO2005046101A2

WO2005046101A2 - Method and system for transmitting encrypted data

Info

Publication number: WO2005046101A2
Application number: PCT/IL2004/001022
Authority: WO
Inventors: Uzi Notev
Original assignee: Israel Aircraft Industries Ltd.
Priority date: 2003-11-11
Filing date: 2004-11-08
Publication date: 2005-05-19
Also published as: IL158832A; WO2005046101A3; IL158832A0

Abstract

System for transmitting encrypted data from an encrypting module (102), the encrypting module (102) being coupled with an energy source (106), the system including at least one transmitter (110), coupled with the energy source (106) via a first power switch, at least one memory module (108) coupled with a respective one of the transmitters (110), the memory module (108) being coupled with the encrypting module (102), via a first data switch, and at least one energy accumulator (114) coupled with the respective transmitter (110), wherein the first data switch connects a respective one of the memory modules (108) to the encrypting module (102) when the respective transmitter (110) is disabled, thereby enabling the respective memory module (108) to receive data from the encrypting module (102), and wherein the first power switch disconnects the energy source (106) from the respective transmitter (110) when the first data switch disconnects the respective memory module from the encrypting module (102), thereby enabling the respective transmitter (110) to transmit the data stored in the respective memory module (108).

Description

METHOD AND SYSTEM FOR TRANSMITTING ENCRYPTED DATA

FIELD OF THE DISCLOSED TECHNIQUE The disclosed technique relates to data transmission in general, and to methods and systems for transmitting encrypted sensitive data, in particular.

BACKGROUND OF THE DISCLOSED TECHNIQUE When a communication system transmits classified data to one or more receivers, either wirelessly or by wire line, third parties can eavesdrop on the classified data either at the endpoϊnts or at the communication medium and thus try to find out the classified data or even the encryption key. Different methods are employed to prevent third parties from extracting the classified data by processing the transmitted signals. Encryption is widely used to prevent the third parties to find out the content of the transmitted classified data. The transmitted signal, generally carries either encrypted classified data or plain unclassified data. The transmitted signal is either in form of data or voice. A classified data communication system operates in such a manner, that the encrypted classified data transmitted by the transmitter is unintentionally (e.g., by leakage) modulated by signals which the various units of the system produce. In this manner, some of the unencrypted data waveform may leak and ride on the transmitted signal. A third party can eavesdrop on the transmitted data either directly or indirectly. Considerable effort is expended on the part of communications engineers to implement hardware and software, to minimize the leakage of the encryption signals to the transmitted encrypted data. Such efforts include design of systems to separate signal carrying conductors, to separate electric power lines, dividing a single power supply to separate portions and drawing power by the transmitting transmitter from a dedicated portion of the power supply, isolating the transmitter by employing optical couplers, transformers, and the like. Reference is now made to Figures 1A, 1 B, 1C and 1 D. Figure 1A is a schematic illustration of a system for transmitting classified data, generally referenced 10, as known in the art. Figure 1 B is a schematic illustration of an unencrypted data waveform produced by an unencrypted data source of the system of Figure 1A, generally referenced 22. Figure 1C is a schematic illustration of an encrypted data waveform produced by an encrypting module of the system of Figure 1 A, generally referenced 24. Figure 1 D is a schematic illustration of a transmitted signal waveform, transmitted by a transmitter of the system of Figure 1A, generally referenced 26. System 10 includes an encrypting module 12, an unencrypted data source 14, an energy source 16 and a transmitter 18. Encrypting module 12 is connected to unencrypted data source 14, energy source 16 and to transmitter 18. Energy source 16 is connected to unencrypted data source 14 and to transmitter 18. Energy source 16 provides electric power to encrypting module 12, unencrypted data source 14 and to transmitter 18. Unencrypted data source 14 produces classified data whose waveform is referenced 22 and provides a respective signal to encrypting module 12. Encrypting module 12 encrypts the unencrypted data, thereby producing encrypted data waveform 24 and provides a signal respective of the encrypted data to transmitter 18. The connections between energy source 16, unencrypted data source 14 and encrypting module 12 allow unencrypted data waveform 22 to reach transmission circuitry (not shown) of transmitter 18. Unencrypted data waveform 22 and encrypted data waveform 24 combine at transmitter 18, thereby modifying encrypted data waveform 24 to produce a modified encrypted data waveform 28. The envelope of modified encrypted data waveform 28 in transmitted signal waveform 26 is in fact unencrypted data waveform 22. Thus, the third party can gain access to the classified data (or voice), according to the envelope of modified encrypted data waveform 28 in transmitted signal waveform 26. Unencrypted data waveform 22 can reach transmitter 18 either directly from encryption module 12, directly from unencrypted data source 14 (e.g., an inductive circuit), or indirectly from either unencrypted data source 14, or encrypting module 12, through energy source 16. US Patent No. 6,169,463 issued to Mohindra et al., and entitled "Quadrature Modulator with Set-and-Forget Carrier Leakage Compensation", is directed to a quadrature modulator and a modulation method. The quadrature modulator is coupled with an antenna through a power amplifier. The quadrature modulator includes a power control input. The quadrature modulator includes an in-phase modulation branch, a quadrature modulation branch, a local oscillator, a carrier leakage measurement means, a state machine and a summing means. The carrier leakage measurement means includes a first series arrangement and a second series arrangement. The in-phase modulation branch receives an in-phase real time signal input l(n) and the quadrature modulation branch receives a quadrature real time signal input Q(n). The state machine receives a control signal and a system clock signal and produces a first monotonously increasing signal sigl and a second monotonously increasing signal sig2. The first series arrangement is coupled with the in-phase modulation branch and with the state machine. The second series arrangement is coupled with the quadrature modulation branch and with the state machine. The local oscillator receives a tuning control input. The local oscillator provides a first carrier signal to the in-phase modulation branch and a second carrier signal, ninety degrees out of phase from the first carrier signal, to the quadrature modulation branch. Sig1 is subtracted from a first filtered analog signal produced by the in-phase modulation branch and this sum is mixed with the first carrier signal, thereby producing a summed mixed quadrature modulated signal lm(t). Sig2 is subtracted from a second filtered analog signal produced by the quadrature modulation branch and this sum is mixed with the second carrier signal, thereby producing a summed mixed quadrature modulated signal Qm(t). The first series arrangement measures a first carrier leakage signal in signal lm(t) and the second series arrangement measures a second carrier leakage in signal Qm(t). The summing means adds signal lm(t) and Qm(t) and provides a quadrature amplitude modulated output signal s(t) to the power amplifier. In order not to introduce DC offsets from the in-phase modulation branch and the quadrature modulation branch, digital input signals to the in-phase modulation branch and to the quadrature modulation branch are set to zero. During carrier leakage compensation, the power amplifier is switched off, in order to prevent transmission of an unmodulated carrier. US Patent No. 6,236,841 issued to Akiya and entitled "Transmission Output Power Control Circuit for Controlling Each of Antennas to Optimal States", is directed to a transmission power control circuit to enable each of a plurality of antennas, to transmit at a predetermined power level. The transmission power control circuit includes a variable attenuator, a final stage amplifier, a detecting circuit, a first switch, the antennas, an automatic power control (APC) processing section, a differential power amplifier, a second switch, a diode and a switching terminal. APC includes a reference voltage, and a comparator. The variable attenuator is connected to a high frequency signal input terminal, the first stage amplifier and to the differential power amplifier. The detecting circuit is connected to the first stage amplifier, the diode and to the first switch. A minus terminal of the comparator is connected to the reference voltage and a plus terminal thereof is connected to the diode. A plus terminal of the differential power amplifier is connected to the output of the comparator and a minus terminal thereof is connected to the second switch. The first switch is connected to the detecting circuit and to the antennas. The switching terminal controls the operation of the first switch to connect the detecting circuit to one of the antennas and also controls the operation of the second switch to connect a voltage source respective of the connected antenna, to the differential power amplifier, via the second switch. The detecting circuit detects the transmission output power amplified by the final stage amplifier. The diode receives the output of the detecting circuit and provides a direct current detection voltage to the comparator. The comparator compares the direct current detection voltage and the reference voltage and provides a comparison voltage to a plus terminal of the differential operation amplifier. The differential operation amplifier provides an attenuation control signal to the variable attenuator. If the voltage detected by the detecting circuit is higher than the reference voltage, then the comparison voltage produced by the APC is high and the output voltage of the attenuation control signal is high. The variable attenuator applies a higher attenuation to the high frequency signal input terminal, the transmission output power of the final stage amplifier is kept in the predetermined power level and the transmission output power of the switched antenna is kept constant. US Patent No. 6,230,022 issued to Sakoda et al., and entitled "Transmitting Method and Apparatus and Sending Power Controlling Method", is directed to a system for mutual control of transmission powers of two mobile stations. The system includes a transmitting apparatus and a communication terminal which communicate via a wireless circuit. The transmitting apparatus includes a first receiving division, a first controlling division and a first transmitting division. The communication terminal includes a second receiving division, a second controlling division and a second transmitting division. The first receiving division receives a first transmission signal from the communication terminal, demodulates the first transmission signal, detects the control data included in the first transmission signal for controlling the sending power and delivers the detected control data to the first controlling division. The first receiving division also measures the received power of the first transmission signal and notifies the measured received power to the first controlling division. The first controlling division produces a power control signal for controlling the sending power of a second transmission signal to be transmitted from the transmitting apparatus to the communication terminal, based on the control data delivered from the first receiving division and supplies the power control signal to the first transmitting division. The first controlling division also produces control data for controlling the sending power of the first transmission signal, based on the measured received power and delivers the control data to the first transmitting division. The first transmitting division controls the sending power of the second transmission signal based on the control data received from the first controlling division. If adjacent-channel interference has a great influence, then the first transmitting division corrects the sending power for the second transmitting signal according to the sending power of the adjacent channel and then transmits the resultant transmission signal to the communication terminal. The second receiving division, the second controlling division and the second transmitting division of the communication terminal operate in a manner as described herein above in connection with the first receiving division, the first controlling division and the first transmitting division, respectively. Thus, the transmitting terminal and the communication terminal mutually detect the electric power of the signal which is sent from the partner and notify the control data of the detected electric power to the partner, thereby controlling the sending power of the partner. US Patent No. 6,381 ,699 issued to Kocher et al., and entitled "Leak- Resistant Cryptographic Method and Apparatus", is directed to a leak-resistant and leak-proof cryptographic system. The system implements systematic authentication, Diffie-Hellman exponential key agreement, EIGamal public key encryption, EIGamal signatures, the Digital Signature Standard, Rivest, Shamir and Adleman (RSA) algorithm and other algorithms. The system operates in three steps. The initialization or key generation step produces secure keying material appropriate for the scheme. The update step cryptographically modifies the secret key material in a manner designed to render useless any information about the secrets that may have previously leaked from the system. The final step performs cryptographic operations, such as producing digital signatures or decrypting messages. US Patent No. 5,574,994 issued to Huang et al., and entitled

"Method of Correcting Carrier Leak in a Transmitter", is directed to a system for suppressing generation of carrier leak in a transmitter and reducing deterioration of communication quality. The system includes a digital signal processor (DSP), a first digital to analog converter (DAC), a second DAC, a first comparator, a second comparator, a first adder, a second adder, a first low pass filter (LPF), a second LPF, a first operational amplifier, a second operational amplifier, a first local oscillator, a second local oscillator, a first quadrature modulator, a second quadrature modulator, a power amplifier, an attenuator and an antenna. The DSP is connected to the first comparator, the second comparator, the first DAC and to the second DAC. The first adder is connected to the first DAC, the first operational amplifier and to the first comparator. The second adder is connected to the second DAC, the second operational amplifier and to the second comparator. The first quadrature modulator is connected with the first LPF, the second LPF, the first oscillator and to the power amplifier. The second quadrature modulator is connected to the first operational amplifier, the second operational amplifier, the second oscillator and to the attenuator. The antenna is connected to the power amplifier and to the attenuator. In correcting the DC elements in the second quadrature modulator, the second quadrature modulator provides DC elements in channels / and Q to the first operational amplifier and the second operational amplifier, respectively. The first operational amplifier and the second operational amplifier provide amplified DC elements l_DC and Q_DC to the first adder and the second adder, respectively. The first comparator compares the output of the first adder with a zero voltage and provides a first input to the DSP. The second comparator compares the output of the second adder with a zero voltage and provides a second input to the DSP. The DSP inputs an / and a Q channel to the first DAC and to the second DAC, respectively. The first adder inputs the sum of the output of the first DAC and the DC element l_DC to the first LPF. The second adder inputs the sum of the output of the second DAC and the DC element Q_DC to the second LPF. The first LPF and the second LPF provide DC elements having an equivalent value and a contrary sign to DC elements l_DC and Q_DC, respectively, to the first quadrature modulator, and thus the DC elements l_DC and Q_DC generated by the second quadrature modulator are cancelled out. US Patent No. 5,566,363 issued to Senda and entitled "Transmission Power Control Circuit and Mobile Communication System Incorporating the Circuit", is directed to a system for controlling the power of a transmission signal. The system includes a comparator, an up/down counter, a clock generator, a DAC, a control circuit, a variable attenuator, a detection circuit, a power amplifier, a branch circuit and a reference voltage source. The comparator is connected to the detection circuit, the reference voltage source and to the up/down counter. The control circuit is connected to the DAC, the clock generator and to the reference voltage. The clock generator is connected to the up/down counter. The DAC is connected to the up/down counter and to the variable attenuator. The variable attenuator is connected to an input terminal and to the power amplifier. The branch circuit is connected to the power amplifier, the detection circuit and to an output terminal. The variable attenuator attenuates the signal at the input terminal and the power amplifier provides an attenuated and amplified signal to the detection circuit. The branch circuit outputs the attenuated and amplified signal to the output terminal, as a power controlled transmission signal. The detection circuit detects the attenuated and amplified signal and produces a detection voltage. The comparator compares the detection voltage with a reference voltage produced by the reference voltage source and provides an output to the up/down counter. The up/down counter up-counts the pulses of the clock generator, when the reference voltage is higher than the detection voltage and down-counts the pulses of the clock generator, when the reference voltage is lower than the detection voltage. The up/down counter varies an attenuation control signal produced thereby, to adjust the amount of attenuation at the variable attenuator, such that the detection voltage and the reference voltage equalize.

SUMMARY OF THE DISCLOSED TECHNIQUE It is an object of the disclosed technique to provide a novel method and system for transmitting encrypted data. In accordance with the disclosed technique, there is thus provided a system for transmitting encrypted data from an encrypting module, wherein the encrypting module is coupled with an energy source. The system includes a transmitter coupled with the energy source via a first power switch, a memory module coupled with the transmitter, and an energy accumulator coupled with the transmitter. The memory module is coupled with the encrypting module, via a first data switch. The first data switch connects the memory module to the encrypting module when the transmitter is disabled, thereby enabling the memory module to receive data from the encrypting module. The first power switch disconnects the energy source from the transmitter when the first data switch disconnects the memory module from the encrypting module, thereby enabling the transmitter to transmit the data stored in the memory module. In accordance with another aspect of the disclosed technique, there is thus provided a system for transmitting encrypted data from an encrypting module, wherein the encrypting module is coupled with a power supply unit. The system includes an energy source, a transmitter coupled with the energy source and a memory module coupled with the transmitter. The memory module is coupled with the encrypting module via a data switch. The data switch connects the memory module to the encrypting module when the transmitter is disabled, thereby enabling the memory module to receive data from the encrypting module. The data switch disconnects the memory module from the encrypting module, thereby enabling the transmitter to transmit the data stored in the memory module. In accordance with a further aspect of the disclosed technique, there is thus provided a method for transmitting encrypted data. The method includes the procedures of storing encrypted data from an encrypting module in a memory module, and disconnecting the memory module from the encrypting module. The method further includes the procedures of disconnecting a transmitter from an energy source which is coupled with the encrypting module and with an unencrypted data source, and transmitting the stored encrypted data by the transmitter using an energy accumulator. In accordance with another aspect of the disclosed technique, there is thus provided a method for transmitting false unencrypted data. The method includes the procedures of producing the false unencrypted data according to encrypted data, storing the false unencrypted data from a false unencrypted envelope generator in a memory module and disconnecting the memory module from the encrypting module. The method further includes the procedures of disconnecting a transmitter from an energy source which is coupled with the encrypting module and an unencrypted data source, and transmitting the stored false unencrypted data by the transmitter, using an energy accumulator.

BRIEF DESCRIPTION OF THE DRAWINGS The disclosed technique will be understood and appreciated more fully from the following detailed description taken in conjunction with the drawings in which: Figure 1 A is a schematic illustration of a system for transmitting classified data, as known in the art; Figure 1 B is a schematic illustration of an unencrypted data waveform produced by an unencrypted data source of the system of Figure 1A; Figure 1 C is a schematic illustration of an encrypted data waveform produced by an encrypting module of the system of Figure 1 A; Figure 1 D is a schematic illustration of a transmitted signal waveform, transmitted by a transmitter of the system of Figure 1A; Figure 2A is a schematic illustration of a system for transmitting encrypted data, constructed and operative in accordance with an embodiment of the disclosed technique; Figure 2B is a schematic illustration of an unencrypted data waveform, produced by an unencrypted data source of the system of Figure 2A; Figure 2C is a schematic illustration of a transmitted data waveform, transmitted by the transmitter of the system of Figure 2A, the transmitted data waveform being substantially identical with an encrypted data waveform, produced by an encrypting module of the system; Figure 3 is a schematic illustration of a system for transmitting encrypted data, constructed and operative in accordance with another embodiment of the disclosed technique; Figure 4 is a schematic illustration of a system for transmitting encrypted data, constructed and operative in accordance with a further embodiment of the disclosed technique; Figure 5 is a schematic illustration of a system for transmitting encrypted data, constructed and operative in accordance with another embodiment of the disclosed technique; Figure 6 is a schematic illustration of a system for transmitting encrypted data, constructed and operative in accordance with a further embodiment of the disclosed technique; Figure 7 is a schematic illustration of a method for operating the system of Figure 2A, operative in accordance with another embodiment of the disclosed technique; and Figure 8 is a schematic illustration of a system for transmitting encrypted data, constructed and operative in accordance with a further embodiment of the disclosed technique.

DETAILED DESCRIPTION OF THE EMBODIMENTS The disclosed technique overcomes the disadvantages of the prior art by providing a system which disconnects the transmitter from any module (e.g., data sources, encryption modules, system power supply units), during transmission. It is noted that according to the disclosed technique, during transmission, the transmitter can only be connected to an independent power source which is used to power the transmitter at that time. During transmission, this power source is disconnected from any module other than the transmitter. When the transmitter is disabled from transmitting, the encrypted data flows to a memory module coupled with the transmitter and the power supply charges a battery which is coupled with the transmitter. When the transmitter is enabled to transmit, the memory module is disconnected from the source of the encrypted data, the battery is disconnected from the power supply and the transmitter transmits the encrypted data stored in the memory module, while drawing power from the battery. The term "data" herein below, refers to speech, voice, sound, text, graphics, numerals, symbols, and the like. Hence, data can be in digital as well as analog format. The term "signal" herein below, refers to an electric signal, electromagnetic signal, optical signal, and the like, which represents data, voice, and the like. The term "unencrypted data" herein below, refers to data which can be interpreted by an electronic device, such as a radio receiver, playback device, and the like, without requiring special provisions to interpret that data. The term "encrypted data" herein below, refers to data which can be interpreted only by incorporating decryption provisions. Reference is now made to Figures 2A, 2B and 2C. Figure 2A is a schematic illustration of a system for transmitting encrypted data, generally referenced 100, constructed and operative in accordance with an embodiment of the disclosed technique. Figure 2B is a schematic illustration of an unencrypted data waveform, generally referenced 200, produced by an unencrypted data source of the system of Figure 2A. Figure 2C is a schematic illustration of a transmitted data waveform, generally referenced 202, transmitted by the transmitter of the system of Figure 2A, the transmitted data waveform being substantially identical with an encrypted data waveform, produced by an encrypting module of the system. System 100 includes an encrypting module 102, an unencrypted data source 104, an energy source 106, a memory module 108, a transmitter 110, an energy accumulator 114, a data switch 116 and a power switch 118. Encrypting module 102 is coupled with unencrypted data source 104, energy source 106 and with data switch 116. Energy source 106 is coupled with unencrypted data source 104 and with power switch 118. Unencrypted data source 104 can include a plurality of devices (not shown) which produce classified data, in which case energy source 106 is coupled with one or more of these devices, in order to supply power to these devices. Memory module 108 is coupled with data switch 116, energy accumulator 114 and with transmitter 110. Transmitter 110 is coupled with energy accumulator 114. Energy accumulator 114 is coupled with power switch 118. Unencrypted data source 104 is a device which produces classified data. For example, in a combat aircraft, unencrypted data source 104 can be a radar, navigation instrument (e.g., altimeter, airspeed indicator, omni-direction finder, distance indicator), ammunition system (e.g., missile, fire gun, laser), mission computer, and the like. Alternatively, unencrypted signal source 104 is a microphone to collect the voice of a person. Further alternatively, unencrypted signal source 104 is a digital or analog speech generator, which can operate in conjunction with a magnetic storage unit (not shown), optical storage unit (not shown), integrated circuit storage unit (not shown), and the like. Encrypting module 102 is a device which encrypts the unencrypted data produced by unencrypted data source 104. Encrypting module 102 is a device, such as a processor, and the like, which employs an encryption algorithm to encrypt the unencrypted data. In the case of speech, encrypting module 102 encodes the speech signal and produces a synthesized signal. Energy source 106 can be an electric power supply (either alternating current or direct current), non-rechargeable battery (i.e., primary battery), rechargeable battery (i.e., secondary battery), fuel cell, renewable power supply (e.g., based on solar energy, wind energy, tidal energy, hydroelectric energy), non-renewable power supply (e.g., based on fossil fuel, alcohol, methanol, natural gas, radioactive material), and the like. Energy accumulator 114 is a device which can be repeatedly charged and which discharges after every charge, such as rechargeable battery, capacitor, and the like. Transmitter 110 can transmit either by wire (e.g., twisted pair, fiber optic cable, coaxial cable, hybrid fiber coaxial cable), or wirelessly (e.g., radio waves, free air optics). Memory module 108 is a first-in-first-out (FIFO) type buffer, last-in-first-out (LIFO), and the like. Data switch 116 is a mechanical switch (e.g., macro-switch, micro-switch), microelectromechanical systems (MEMS) switch, optical switch, electronic switch (e.g., transistor, Triac, integrated circuit), electronic switch, and the like. An optical switch can be turned on and off by alternately moving an opaque body out of or into an optical path, respectively. Power switch 118 is a mechanical switch (e.g., macro-switch, micro-switch), MEMS switch, electronic switch (e.g., transistor, Triac, SCR, integrated circuit), electronic switch, and the like. Each of encrypting module 102 and unencrypted data source

104 continuously draws power from energy source 106, in order to operate. The unencrypted data produced by unencrypted data source 104 has a waveform such as unencrypted data waveform 200. It is noted that waveform 200 can be in any form known in the art. When transmitter 110 is disabled from transmitting, data switch 116 and power switch 118 are closed. Thus, encrypted data produced by encrypting module 102 is stored in memory module 108 and energy source 106 charges energy accumulator 114. Moreover, memory module 108 draws power from energy accumulator 114 in order to operate. The encrypted data has a waveform such as encrypted data waveform 202. Prior to or at the transmission stage, data switch 116 and power switch 118 are opened. When transmitter 110 is enabled to transmit, transmitter 110 draws power from energy accumulator 114 to transmit the encrypted data which was previously stored in memory module 108. For this purpose, memory module 108 draws power from energy accumulator 114. If during transmission, encrypting module 102 is connected with transmitter 110 by memory module 108, then unencrypted data waveform 200 can leak to transmitter 110 through encrypting module 102 and memory module 108. Since during transmission, transmitter 110 is connected neither with encrypting module 102 nor unencrypted data source 104, unencrypted data waveform 200 can not leak to transmitter 110. If during transmission, encrypting module 102 and unencrypted data source 104 are connected with transmitter 110, by energy source 106 and energy accumulator 114, then unencrypted data waveform 200 can leak to transmitter 110, through either or all of encrypting module 102, energy source 106 and energy accumulator 114. Since during transmission, transmitter 110 is connected neither with encrypting module 102 nor unencrypted data source 104, unencrypted data waveform 200 can not leak to transmitter 110. Therefore, the signals produced by encrypting module 102 and unencrypted data source 104 do not influence encrypted data waveform 202 which transmitter 110 transmits. The transmitted signal has a waveform substantially identical with encrypted data waveform 202. Since transmitted data waveform 202 is substantially free from any traces of the unencrypted data (i.e., unencrypted data waveform 200), a receiver (not shown) which receives the transmitted signal from transmitter 110, can not gain access to the transmitted signal without decrypting the transmitted signal. The cycle of closing and opening of data switch 116 and power switch 118 described herein above, is repeated for subsequent transmission sessions. Alternatively, the energy source and the energy accumulator are interchanged (i.e., the energy source is coupled with the transmitter, the memory module and with the power switch, and the energy accumulator is coupled with the power switch, the encrypting module and with the unencrypted data source). In this case, the energy source normally provides power to the transmitter and to the memory module, and the energy source is normally coupled with the energy accumulator to charge the energy accumulator. The energy source is disconnected from the energy accumulator only when the transmitter is enabled to transmit. Further alternatively, instead of direct coupling with the energy accumulator, the memory module can be coupled with the energy source by a first power switch and with the energy accumulator by a second power switch. When the transmitter is disabled to transmit, the first power switch is closed and the second power switch is open, thereby allowing the memory module to draw power from the energy source, in order to store the encrypted signal waveform. When the transmitter is enabled to transmit, the first power switch is opened and the second power switch is closed, thereby isolating the memory module from the energy source, the encrypting module and the unencrypted signal source. Thus, the memory module can draw power from the energy accumulator to supply the encrypted signal to the transmitter. The encrypting module and the memory module can be provided with a signal return path, or be directly grounded. In this case, the data switch disconnects also the signal return path or the ground connection, when the transmitter is enabled to transmit. Additionally, system 100 can include an analog to digital converter - ADC (not shown) and a digital to analog converter - DAC (not shown). The ADC is coupled either between data switch 116 and memory module 108, or between data switch 116 and encrypting module 102. Alternatively, the ADC is incorporated with encrypting module 102. Further alternatively, the ADC is incorporated with memory module 108. The DAC is coupled between memory module 108 and transmitter 110. When data switch 116 is closed, the encrypted data in analog format, flows from encrypting module 102 to memory module 108, through the ADC. The ADC converts the analog encrypted data to digital format and the digital encrypted data is stored in memory module 108. When transmitter 110 is enabled to transmit, transmitter 110 retrieves the encrypted data from memory module 108, through the DAC, while the DAC converts the digital encrypted data to analog format. Additionally, the system can include a timing mechanism (not shown), in order to determine when the transmitter is to transmit the encrypted signal, when the transmitter is enabled to transmit. The timing mechanism can be in various forms. For example, a first timing unit (not shown) is incorporated with either the encrypting module or the unencrypted signal source or both, and a second timing unit (not shown) is incorporated with the transmitter, wherein the first timing unit and the second timing unit are coupled via a timing switch (not shown). Each of the first timing unit and the second timing unit are in form of a time keeper, such as a crystal, an atomic clock, and the like. Each of the first timing unit and the second timing unit can be incorporated with a processor (not shown). When the transmitter is disabled to transmit, the first timing unit determines the transmission time, the timing switch is closed, and the first timing switch transmits the determined transmission time to the second timing switch. When the transmitter is enabled to transmit, the power switch, the signal switch and the timing switch are opened, and the transmitter commences transmission at the determined transmission time. The precision of both the first timing unit and the second timing unit can be substantially the same, in which case no synchronization between the two is necessary. Alternatively, the first timing unit is more precise than the second timing unit, in which case the first timing unit synchronizes the second timing unit when the timing switch is closed. It is noted that a timing signal transmitted from the first timing unit to the second timing unit can include additional parameters, such as transmission power, transmission frequency, transmission duration, and the like. In another example, the second timing unit determines the transmission time and transmits the determined transmission time to the first timing unit (i.e., the second timing unit notifies the encrypting module, that the transmitter is available for transmission at a certain time and for a certain period). In this case, the transmission of the encrypted signal from the encryption module to the memory unit, and the operation of the power switch, the signal switch and the timing switch are controlled, in order to meet the transmission time and the transmission period. In a further example, the first timing unit, the second timing unit and the timing switch are absent from the system. When the power switch and the signal switch are opened, the transmitter detects this opening and commences transmission for a predetermined period, after another predetermined period following the opening. Reference is now made to Figure 3, which is a schematic illustration of a system for transmitting encrypted data, generally referenced 230, constructed and operative in accordance with another embodiment of the disclosed technique. System 230 includes an encrypting module 232, an unencrypted data source 234, an energy source 236, a memory module 238, a transmitter 240, an energy accumulator 244, a data switch 246 and a power switch 248. Encrypting module 232 is coupled with unencrypted data source 234, energy source 236 and with data switch 246. Energy source 236 is coupled with unencrypted data source 234 and with power switch 248. Memory module 238 is coupled with data switch 246 and with transmitter 240. Power 5 switch 248 is coupled with transmitter 240, memory module 238 and with energy accumulator 244, at a junction 250 between transmitter 240, memory module 238 and energy accumulator 244. When transmitter 240 is disabled from transmitting, data switch 246 and power switch 248 are closed. In this mode, encrypting moduleo 232 is connected with memory module 238 and energy source 236 is connected with transmitter 240, memory module 238 and energy accumulator 244. Thus, the encrypted data produced by encrypting module 232 can be stored in memory module 238, transmitter 240 can draw power from both energy source 236 and energy accumulator 244,5 and energy accumulator 244 can be charged by energy source 236. Prior to and during the transmission stage, data switch 246 and power switch 248 are opened, in which case transmitter 240 and memory module 238 draw power from energy accumulator 244, to transmit the encrypted data stored in memory module 238.o Reference is now made to Figure 4, which is a schematic illustration of a system for transmitting encrypted data, generally referenced 270, constructed and operative in accordance with a further embodiment of the disclosed technique. System 270 includes an encrypting module 272, an unencrypted data source 274, energy sources5 276 and 278, a memory module 280, a transmitter 282 and a data switch 286. Each of energy sources 276 and 278 is similar to either of energy sources 106 (Figure 2A) and 114, as described herein above. Energy source 276 can also be referred to as "a power supply unit".0 Encrypting module 272 is coupled with unencrypted data source 274, energy source 276 and with data switch 286. Energy source 276 is coupled with unencrypted data source 274. Memory module 280 is coupled with data switch 286, energy source 278 and with transmitter 282. Energy source 278 is coupled with transmitter 282. Energy source 276 provides electric power to encrypting module 272 and to unencrypted data source 274. Energy source 278 provides electric power to transmitter 282. When transmitter 282 is disabled from transmitting, data switch 286 is closed. In this mode, encrypting module 272 is connected with memory module 280 and the encrypted data produced by encrypting module 272 can be stored in memory module 280. Prior to and during the transmission stage, data switch 286 is opened, in which case transmitter 282 and memory module 280 draw power from energy source 278, to transmit the encrypted data stored in memory module 280. In this case transmitter 282 and memory module 280 draw electric power from energy source 278 which is dedicated to transmitter 282 and to memory module 280, wherein energy source 278 is never connected with either encrypting module 272 or unencrypted data source 274. Hence, an unencrypted data waveform similar to unencrypted data waveform 200 (Figure 2B), does not leak to transmitter 282, while transmitter 282 is enabled to transmit. According to another aspect of the disclosed technique, a transmitter transmits concatenated portions of encrypted data from a plurality of memory modules, in sequence, while drawing power from a plurality of energy accumulators, in sequence. The memory module from which the stored portion of the encrypted data is retrieved in order to be transmitted, is disconnected from the encrypting module, when the transmitter is transmitting this portion of the encrypted data. Likewise, the energy accumulator from which the transmitter draws power, is disconnected from the energy source, while the transmitter is transmitting encrypted data. Thus, during transmission, the transmitter is disconnected from the encrypting module and from the unencrypted data source, and the unencrypted data waveform of the encrypted data can not leak to the transmitter. When the transmitter is transmitting data stored in one memory module, other parts of data are stored in other memory modules and while the transmitter is drawing power from one energy accumulator, other energy accumulators are charged with power from the energy source. Reference is now made to Figure 5, which is a schematic illustration of a system for transmitting encrypted data, generally referenced 310, constructed and operative in accordance with another embodiment of the disclosed technique. System 310 includes a plurality of memory modules 312-,, 312₂ and 312_N, a transmitter 314, a plurality of energy accumulators 318ι, 318₂ and 318_N, an energy source 320, a first power switch 322, a second power switch 324, a first data switch 326 and a second data switch 328. Each of energy accumulators 318-ι, 318₂ and 318N is similar to energy accumulator 114 (Figure 2A), as described herein above. Each of first power switch 322 and second power switch 324 is a one-pole multiple-throw switch, wherein the number of throws is at least equal to the number of energy accumulators 318-ι , 318₂ and 318N- Each of first data switch 326 and second data switch 328 is a one-pole multiple-throw switch, wherein the number of throws is at least equal to the number of memory modules 312 ₅ 312₂ and 312_N. First data switch 326 is coupled between memory modules 312^ 312₂ and 312_N and an encrypting module (not shown). The encrypting module is coupled with an unencrypted data source (not shown). Second data switch 328 is coupled between memory modules 312_η, 312 and 312_N and transmitter 314. First power switch 322 is coupled between energy source 320 and energy accumulators 318_{1 s} 318₂ and 318_N. Second power switch 324 is coupled between energy accumulators 318_{1 ;} 318₂ and 318N and transmitter 314. Energy source 320 is coupled with the encrypting module and with one or more unencrypted data sources. First data switch 326 can connect any of memory modules 312-(, 312₂ and 312_N with the encrypting module. Second data switch 328 can connect any of memory modules 312^ 312₂ and 312_N with transmitter 314. First power switch 322 can connect any of energy accumulators 318^ 318₂ and 318_N with energy source 320. Second power switch 324 can connect any of energy accumulators 318^ 318₂ and 318_N with transmitter 314. System 310 can be utilized for transmitting almost continuously, a large amount of classified data by one transmitter, from one encrypting module. This is the case where the batch of encrypted data is larger than the capacity of a single memory module, and where the charge of a single energy accumulator is not enough to supply power to the transmitter, to transmit the entire batch of encrypted data. Memory modules 312_Λ , 312₂ and 312 are used to store the concatenated portions of the encrypted data. Transmitter 314 is connected with each of memory modules 312 _s 312₂ and 312_N one at a time and with each of energy accumulators 318-ι, 318₂ and 318_N, one at a time. When a specific memory module is connected to transmitter 314, this specific memory module is disconnected from the encrypting module, thereby substantially preventing the unencrypted data waveform of the classified data to leak to transmitter 314. When transmitter 314 is connected to a specific energy accumulator to draw power from this energy accumulator, this specific energy accumulator is disconnected from energy source 320, in order to substantially prevent the unencrypted data waveform of the classified data to leak to transmitter 314. Following is a description of operation of system 310 to transmit a batch of encrypted data, almost continuously. Prior to the start of transmission, first data switch 326 connects memory module 312_Λ to the encrypting module, thereby allowing the encrypting module to store a first portion of a concatenated encrypted data in memory module 312^ Furthermore, prior to the start of transmission, first power switch 322 connects energy accumulator 318_! with energy source 320, thereby allowing energy source 320 to charge energy accumulator 318₁. In the following description concerning the transmission stage, the connections and disconnections take place substantially simultaneously. At the start of transmission, first data switch 326 disconnects memory module 312ι from the encrypting module and connects memory module 312₂ to the encrypting module, thereby allowing encrypting module to store a second portion of the concatenated encrypted data in memory module 312₂. First power switch 322 disconnects energy accumulator 318 from energy source 320 and connects energy accumulator 318₂ with energy source 320, thereby allowing energy source 320 to charge energy accumulator 318₂. Second power switch 324 connects transmitter 314 with energy accumulator 318^ and second data switch 328 connects transmitter 314 with memory module 31 . . At this instant, transmitter 314 transmits the first portion of the concatenated encrypted data which was stored in memory module 312^ while drawing power from energy accumulator 318^ Memory module 312i is not connected with the encrypting module, energy accumulator 318i is not connected with energy source 320, and transmitter 314 is connected neither with the encrypting module nor with energy source 320. Thus, during the transmission of the first portion of the concatenated encrypted data, the unencrypted data waveform of the classified data can leak neither from the unencrypted data source nor from the encrypting module, to transmitter 314. Furthermore, during the transmission of the first portion of the concatenated encrypted data, the second portion of the concatenated encrypted data is stored in memory module 312₂ and energy source 320 charges energy accumulator 318₂. It is noted that the second portion of the concatenated encrypted data can be stored in memory module 312₂, anytime transmitter 314 is not connected with memory module 312₂ or anytime transmitter 314 is not transmitting. It is further noted that energy source 320 charges energy accumulator 318₂ anytime transmitter 314 is not connected with energy accumulator 318₂ or transmitter 314 is not transmitting. Following is a description of operation of system 310, while transmitting the second portion of the concatenated encrypted data. First data switch 326 disconnects memory module 312₂ from the encrypting module and connects memory module 312_N with the encrypting module. First power switch 322 disconnects energy accumulator 318₂ from energy source 320 and connects energy accumulator 318_N to energy source 320. Second power switch 324 disconnects transmitter 314 from energy accumulator 318_! and connects transmitter 314 to energy accumulator 318₂. Now, transmitter 314 can transmit the second portion of the concatenated encrypted data which was stored in memory module 312₂ while drawing power from energy accumulator 318₂. During the transmission of the second portion of the concatenated encrypted data, the n^th portion of the concatenated encrypted data is stored in memory module 312_N and energy source 320 charges energy accumulator 318_N- System 310 operates in a similar manner while transmitting the n^th portion of the concatenated encrypted data. It is noted that energy accumulators 318-ι , 318₂ and 318_N can be connected with energy source 320 and with transmitter 314 in any sequence and not necessarily in the numerical sequence which was described herein above, as long as the same energy accumulator which is connected with transmitter 314 is not simultaneously connected with energy source 320. Likewise, it is not necessary for memory modules 312ι, 312₂ and 312_N to be connected with the encrypting module in the numerical sequence described herein above, as long as the same memory module which is connected with the encrypting module, is not connected simultaneously with transmitter 314. It is further noted that not all memory modules 312ι, 312₂ and 312_N have to be utilized to store concatenated portions of the encrypted data and likewise not all energy accumulators 318^ , 318₂ and 318_N have to be utilized to provide power to transmitter 314. It is further noted that the switching sequence of memory modules 312-ι , 312₂ need not coincide with the switching sequence of energy accumulators 318-ι, 318₂ and 318_N (i.e., transmitter 314 can continue to draw power from a single energy accumulator while switching to different memory modules in order to transmit different portions of the encrypted data). Alternatively, energy source 320 can charge more than one energy accumulator simultaneously (i.e., energy source 320 can be connected to a plurality of energy accumulators at the same time) and transmitter 314 can draw power from more than one energy accumulator simultaneously (i.e., transmitter 314 can be connected to a plurality of energy accumulators at the same time). System 310 can operate in this manner, as long as the same energy accumulator which is connected with transmitter 314, is not connected with energy source 320. According to a further aspect of the disclosed technique, a transmission controller controls the transmission of encrypted data by a plurality of transmitters, in sequence, thereby allowing each transmitter to transmit in a different time slot and at substantially the same frequency. While a single transmitter is transmitting encrypted data stored in its memory module, this memory module is disconnected from the encrypting module and the energy accumulator from which the transmitter draws power, is disconnected from the energy source. Furthermore, during transmission, the transmitter is disconnected from the transmission controller. Thus, during transmission, unencrypted data waveform of the encrypted data can not leak to the transmitter. When a transmitter is idle, encrypted data can be stored in its memory module and the energy source which is to supply power to this transmitter, can be charged with power from the energy source. Reference is now made to Figure 6, which is a schematic illustration of a system for transmitting encrypted data, generally referenced 350, constructed and operative in accordance with a further embodiment of the disclosed technique. System 350 includes a plurality of transmitters 352-ι, 352₂ and 352_N, an encrypting module 356, a plurality of energy accumulators 358ι, 358₂ and 358_N, an energy source 360, a transmission controller 362, a power switch assembly 364, a transmission switch assembly 366 and a data switch assembly 368. Transmitters 352^ 352₂ and 352_N include memory modules 370-ι, 370₂ and 370N, respectively. Data switch assembly 368 includes a plurality of switches 372-ι , 372₂ and 372_N. Transmission switch assembly 366 includes a plurality of switches 374_{1 (} 374₂ and 374_N. Power switch assembly 364 includes a plurality of switches 376^ 376₂ and 376_N. Transmitters 352^ 352₂ and 352_N are coupled with energy accumulators 358^ 358₂ and 358_N, respectively. Transmission controller 362 is coupled with power switch assembly 364 and with data switch assembly 368. Energy source 360 is coupled with encrypting module 356, at least one unencrypted data source (not shown) and with transmission controller 362. Switches 372ι, 372₂ and 372_N are coupled with encrypting module 365 on one side and with memory modules 370^ 370₂ and 370_N, respectively, on the other side thereof. Switches 374_! , 374₂ and 374_N are coupled with transmission controller 362 on one side and with transmitters 352-ι , 352₂ and 352_N, respectively, on the other side thereof. Switches 376_! , 376₂ and 376_N are coupled with energy source 360 on one side and with energy accumulators 358ι, 358₂ and 358_N, respectively, on the other side thereof. Transmission controller 362 controls the operation of switches 372_! , 372₂, 372_N, 374ι, 374₂, 374_N, 376_! , 376₂ and 376_N, such that when transmission controller 362 enables one of transmitters 352_!, 352₂ and 352_N, this specific transmitter is disconnected from transmission controller 362. Simultaneously, the memory module of the enabled transmitter is disconnected from encrypting module 356 and the energy accumulator from which the enabled transmitter draws power, is disconnected from energy source 360, thereby substantially preventing unencrypted data waveform of the encrypted data, to leak to the enabled transmitter. In the meantime, encrypted data can be stored in memory modules of other transmitters which are disabled to transmit, and the energy accumulators of the disabled transmitters are charged with power from energy source 360. For example, transmission controller 362 enables transmitter

352_!, by opening switch 374 , which incidentally disconnects transmitter 352_! from transmission controller 362. Substantially simultaneously, transmission controller 362 directs switches 372_! and 376_! to open, which disconnect memory module 370ι from encrypting module 356 and energy accumulator 358_! from energy source 360, respectively. At the same time, transmission controller 362 closes at least one of switches 372₂, 372_N, 374₂, 374_N, 376₂ and 376_N, thereby allowing encrypting module 356 to store encrypted data in at least one of memory modules 370₂ and 370_N, and allowing energy source 360 to charge at least one of energy accumulators 358₂ and 358_N. Thus, transmitter 352_! is disconnected from encrypting module 356, from transmission controller 362 and from energy source 360, while transmitting encrypted data, thereby substantially preventing unencrypted data waveform of the encrypted data to leak to transmitter 352_!. It is noted that transmission controller 362 is coupled with energy source 360, power switch assembly 364 and with data switch assembly 368 and that during transmission, unencrypted data waveform of the transmitted encrypted data, can leak to the transmitting transmitter. For this reason it is imperative for the transmitting transmitter to be disconnected from transmission controller 362, by opening an appropriate one of switches 374_!, 374₂ and 374_N. It is further noted that each of switches 372 , 372₂ and 372_N can be connected with a different encrypting module, similar to encrypting module 356. Each of transmitters 352_!, 352₂ and 352_N transmit in a different band and to a different destination. Alternatively, each of transmitters 352_!, 352₂ and 352_N, transmit on the same band, in which case a token protocol is employed to switch between transmitters 352_!, 352₂ and 352_N. Reference is now made to Figure 7, which is a schematic illustration of a method for operating the system of Figure 2A, operative in accordance with another embodiment of the disclosed technique. In procedure 400, encrypted data from an encrypting module is stored in a memory module. With reference to Figure 2A, while transmitter 110 is idle, data switch 116 is closed, thereby allowing encrypting module 102 to store encrypted data in memory module 108. In procedure 402, the memory module is disconnected from the encrypting module. With reference to Figure 2A, either before or during the time transmitter 110 is enabled to transmit, memory module 108 is disconnected from encrypting module 102, thereby substantially preventing the unencrypted data waveform of the encrypted data, to leak to transmitter 110, through memory module 108. In procedure 404, a transmitter is disconnected from an energy source which is coupled with the encrypting module. With reference to Figure 2A, either before or during transmission of encrypted data by transmitter 110, power switch 118 is opened, thereby disconnecting transmitter 110 from energy source 106. Thus, the unencrypted data waveform of the encrypted data can not to leak to transmitter 110, through energy accumulator 114. Alternatively, a first energy source which provides electric power to the encrypting module and to the unencrypted data source, can be permanently disconnected from a second energy source which provides electric power to the transmitter and to the memory module, as described herein above in connection with Figure 4. In this case, the first energy source and the second energy source are physically and permanently disconnected and the unencrypted data waveform can not leak to the transmitter, while the transmitter is enabled to transmit. In procedure 406, the stored encrypted data is transmitted by the transmitter, using an isolated energy accumulator. With reference to Figure 2A, transmitter 110 transmits the encrypted data which was stored in memory module 108 in procedure 400, while data switch 116 and power switch 118 are both open. Thus, during transmission, transmitter 110 is disconnected from encrypting module 102 and from unencrypted data source 104, thereby substantially preventing the unencrypted data waveform of the encrypted data, to leak to transmitter 110. Reference is now made to Figure 8, which is a schematic illustration of a system for transmitting encrypted data, generally referenced 430, constructed and operative in accordance with a further embodiment of the disclosed technique. System 430 includes an encrypting module 432, an unencrypted data source 434, an energy source 436, a false unencrypted envelope generator (FUEG) 438, a memory module 440, a transmitter 442, an energy accumulator 446, a power switch 448 and a data switch 450. Encrypting module 432 is coupled with unencrypted data source 434, energy source 436 and with data switch 450. FUEG 438 is coupled with data switch 450 and with memory module 440. Transmitter 442 is coupled with memory module 440 and with energy accumulator 446. Power switch 448 is coupled with energy accumulator 446 and with energy source 436. Energy source 436 is coupled with unencrypted data source 434. Energy accumulator 446 is coupled with memory module 440. FUEG 438 is a device which produces false (i.e., misleading) unencrypted data, according to encrypted data. In the following example, unencrypted data source 434 is a target finder (not shown) in a combat aircraft (not shown), where unencrypted data source 434 produces unencrypted (i.e., classified) data respective of the coordinates of a target (not shown). Alternatively, FUEG 438 is a device which produces a noise of an amplitude sufficient to mask any signal respective of the unencrypted data, which might leak to transmitter 442. Further alternatively, FUEG 438 is a device which produces both the false unencrypted data and the masking noise. Encrypting module 432 produces encrypted data according to the unencrypted data received from unencrypted data source 434. Encrypting module 432 and unencrypted data source 434 draw power from energy source 436, in order to operate. When transmitter 442 is idle and not enabled to transmit, data switch 450 is closed, wherein FUEG 438 produces false unencrypted data according to the encrypted data received from encrypting module 432. This false unencrypted data can be for example, false coordinates of the target in an unencrypted form, which a third party (e.g., an enemy aircraft) can understand without having to decrypt it. This false unencrypted data is stored in memory module 440. When transmitter 442 is idle, power switch 448 is also closed, thereby enabling energy source 436 to charge energy accumulator 446. When transmitter 442 is ready to transmit, power switch 448 and data switch 450 are opened substantially simultaneously, thereby disconnecting transmitter 442 from encrypting module 432 and unencrypted data source 434. Transmitter 442, then transmits the false unencrypted data which was stored in memory module 440, while drawing power from energy accumulator 446. Since during transmission transmitter 442 is connected neither with encrypting module 432 nor with unencrypted data source 434, the unencrypted data can not leak to transmitter 442 from either one of energy source 436, energy accumulator 446, FUEG 438, or memory module 440. However, the third party, for example a receiver (not shown) of the enemy aircraft which listens to transmitter 442, can receive the false unencrypted data, thereby being misinformed about the true coordinates of the target, without having to decrypt the received data. Alternatively, the memory module is directly coupled with data switch 450, a summer is coupled between the memory module and the transmitter, and the FUEG is coupled with the summer. In this case, the summer adds the signal produced by the FUEG to the output of the memory module, and the summer provides this summation to the transmitter. It will be appreciated by persons skilled in the art that the disclosed technique is not limited to what has been particularly shown and described hereinabove. Rather the scope of the disclosed technique is defined only by the claims, which follow.

Claims

1. System for transmitting encrypted data from an encrypting module, said encrypting module being coupled with an energy source, the system comprising: at least one transmitter, coupled with said energy source via a first power switch; at least one memory module coupled with a respective one of said at least one transmitter, said at least one memory module being coupled with said encrypting module, via a first data switch; and at least one energy accumulator coupled with said respective transmitter, wherein said first data switch connects a respective one of said at least one memory module to said encrypting module when said respective transmitter is disabled, thereby enabling said respective memory module to receive data from said encrypting module, and wherein said first power switch disconnects said energy source from said respective transmitter when said first data switch disconnects said respective memory module from said encrypting module, thereby enabling said respective transmitter to transmit said data stored in said respective memory module.

2. The system according to claim 1 , wherein said at least one energy accumulator is coupled between said at least one transmitter and said first power switch.

3. The system according to claim 1 , wherein said first power switch is coupled between said energy source and a junction connecting said at least one energy accumulator and said at least one transmitter, wherein said first power switch disconnects said energy source from said respective transmitter and said energy accumulator, when said respective transmitter is enabled, and wherein said first power switch connects said energy source to said respective transmitter and said energy accumulator, when said respective transmitter is disabled.

4. The system according to claim 1 , further comprising a second power switch coupled with said at least one transmitter, wherein said at least one energy accumulator is coupled between said first power switch and said second power switch, and wherein said first power switch is coupled with said energy source.

5. The system according to claim 1 , wherein said at least one memory module comprises a plurality of memory modules, said system further comprises a second data switch coupled between said at least one transmitter and said memory modules, and wherein said first data switch connects a selected one of said memory modules to said encrypting module, when said second data switch disconnects said selected memory module from said at least one transmitter, and wherein said first data switch disconnects another selected one of said memory modules from said encrypting module, when said second data switch connects said other selected memory module to said at least one transmitter.

6. The system according to claim 1 , further comprising at least one unencrypted data source coupled with said encrypting module and with said energy source, wherein said encrypting module encrypts unencrypted data produced by said at least one unencrypted data source.

7. The system according to claim 1 , wherein the said at least one transmitter is selected from the list consisting of: wireless; and wired.

5 8. The system according to claim 1 , further comprising: a transmission switch ; and a transmission controller coupled with said transmission switch, said first data switch, said first power switch and with said energyo source, wherein simultaneously said transmission controller directs said first data switch to disconnect at least a selected one of said at least one memory module from said encrypting module, said transmission controller directs said first power switch to disconnect said energy5 source from at least a selected one of said at least one transmitter respective of said selected at least one memory module, and said transmission controller further directs said transmission switch to disconnect said transmission controller from said selected at least one transmitter, at least during the time said selected at least oneo transmitter is enabled to transmit, and wherein simultaneously said transmission controller directs said first data switch to connect said selected at least one memory module to said selected at least one transmitter, said transmission controller directs said power switch to connect said energy source to said5 selected at least one transmitter, and said transmission controller directs said transmission switch to connect said transmission controller to said selected at least one transmitter, at least during the time said selected at least one transmitter is disabled from transmitting.0

9. The system according to claim 8, wherein said first power switch is coupled between said at least one energy accumulator and said energy source, wherein said transmission controller directs said first power switch to disconnect said energy source from at least a selected one of said at least one energy accumulator respective of said selected at least one transmitter, at least during the time said selected at least one transmitter is enabled to transmit, and wherein said transmission controller directs said power switch to connect said energy source to said selected at least one energy accumulator, at least during the time said selected at least one transmitter is disabled from transmitting.

10. The system according to claim 1 , wherein said at least one energy accumulator is selected from the list consisting of: capacitor; renewable power supply; non-renewable power supply; electric power supply; rechargeable battery; non-rechargeable battery; and fuel cell.

1 1 . The system according to claim 1 , wherein each of said at least one transmitter transmits said encrypted data in a different time slot.

12. The system according to claim 1 , further comprising a false unencrypted envelope generator coupled with said at least one transmitter, wherein said false unencrypted envelope generator produces false unencrypted data according to said data received from said encrypting module, and wherein said false unencrypted envelope generator provides said false unencrypted data to said at least one transmitter at least during transmission by said at least one transmitter.

13. The system according to claim 1 , further comprising at least one timing mechanism coupled with said respective at least one transmitter, a respective one of said at least one timing mechanism determining at least one of transmission time, transmission period and at least one transmission parameter, for said respective at least one transmitter, said respective at least one timing mechanism at least directing said respective at least one transmitter to commence transmitting at a respective one of said transmission time, for a respective one of said transmission period, according to a respective one of said transmission parameter.

14. System for transmitting encrypted data from an encrypting module, said encrypting module being coupled with a power supply unit, the system comprising: at least one energy source; at least one transmitter, coupled with said at least one energy source; and at least one memory module coupled with a respective one of said at least one transmitter, said at least one memory module being coupled with said encrypting module, via a data switch, wherein said data switch connects a respective one of said at least one memory module to said encrypting module when said respective transmitter is disabled, thereby enabling said respective memory module to receive data from said encrypting module, and wherein said data switch disconnects said respective memory module from said encrypting module, thereby enabling said respective transmitter to transmit said data stored in said respective memory module.

15. The system according to claim 14, wherein each of said power supply unit and said at least one energy source, is selected from the list consisting of: capacitor; renewable power supply; non-renewable power supply; electric power supply; rechargeable battery; non-rechargeable battery; and fuel cell.

16. The system according to claim 14, further comprising at least one unencrypted data source coupled with said encrypting module and with said power supply unit, wherein said encrypting module encrypts unencrypted data produced by said at least one unencrypted data source.

17. Method for transmitting encrypted data, the method comprising the procedures of: storing encrypted data from an encrypting module in a memory module; disconnecting said memory module from said encrypting module; disconnecting a transmitter from an energy source which is coupled with at least one of said encrypting module and an unencrypted data source; and transmitting said stored encrypted data by said transmitter, using an energy accumulator.

18. The method according to claim 17, further comprising a procedure of disconnecting said energy accumulator from said energy source, before performing said procedure of transmitting.

19. The method according to claim 17, further comprising a preliminary procedure of determining at least one of transmission time, transmission period, and at least one transmission parameter.

20. Method for transmitting false unencrypted data, the method comprising the procedures of: producing said false unencrypted data according to encrypted data; storing said false unencrypted data from a false unencrypted envelope generator, in a memory module; disconnecting said memory module from said encrypting module; disconnecting a transmitter from an energy source which is coupled with at least one of said encrypting module and an unencrypted data source; and transmitting said stored false unencrypted data by said transmitter, using an energy accumulator.

21 . System for transmitting encrypted data, according to any of claims 1 -16 substantially as described hereinabove.

22. System for transmitting encrypted data, according to any of claims 1 -16 substantially as illustrated in any of the drawings.

23. Method for transmitting encrypted data, according to any of claims 17-19 substantially as described hereinabove.

24. Method for transmitting encrypted data, according to any of claims 17-19 substantially as illustrated in any of the drawings.

25. Method for transmitting false unencrypted data, according to claim 20 substantially as described hereinabove.

26. Method for transmitting false unencrypted data, according to claim 20 substantially as illustrated in any of the drawings.