Applied Optics

4 stars based on 38 reviews

An optical communications network incorporating photonic layer security, with secure key exchange without loss of data, and a method of operating the network are disclosed. The network comprises a transmit optical encryption system with a binary key code and a receive side. The transmit side includes first and second scramblers and a transmit side switch; and the receive side includes first and second descramblers and a receive side switch.

The scramblers use encryption keys to encrypt optical signals, and the descramblers use the encryption keys optical encryption system with a binary key code decrypt the encrypted optical signals. The encryption keys can be updated randomly and at will by installing new encryption keys on the scramblers and descramblers, and the transmit side and receive side switches are synchronized so that all of the optical signals that are encrypted using a new or updated encryption key are decrypted using the same new or updated encryption key.

The present invention generally relates to optical code division multiplexed communication networks incorporating photon layer security. Various communications schemes have been used to increase data throughput and to decrease data error rates as well as to generally improve the performance of communications channels.

As an example, frequency division multiple access: SPE-CDMA is a form of spread spectrum communications that enables multiple data streams or channels to share a single transmission band at the same time. Basically, in SPE-CDMA, the bandwidth of the data to be transmitted user data is much less than the bandwidth of the transmission band. The pseudonoise keys are selected to mimic Gaussian noise e.

One pseudonoise key is used to modulate the user data for a given channel. That is, all of the channels are transmitted at the same time in the same frequency band.

Thus, the data is returned to approximately the size of its original bandwidth, while the noise remains spread over the much larger transmission band. The power control for each user can also help to reduce noise from other users. Such cellular systems typically operate at between MHz and 2 GHz, though the individual frequency bands may be only a few MHz wide.

The increased number of users in the transmission band merely increases the noise to contend with. As an example, a plurality of subscriber stations may be interconnected to the hub by a respective bidirectional optical fiber link. Each subscriber station has a transmitter capable of transmitting optical signals, and each station also has a receiver capable of receiving transmitted signals from all of the various optical encryption system with a binary key code in the network.

The optical hub receives optical signals over optical fiber links from each of the transmitters and transmits optical signals over optical fiber links to all of the receivers. An optical pulse is transmitted to a selected one of a plurality of potential receiving stations by coding the pulse in a manner such that it is detectable by the selected receiving station but not by the other receiving stations.

Each receiving station is provided with optical receiving equipment capable of regenerating an optical pulse when it receives a pattern of chips coded in accordance with its own unique sequence but cannot regenerate the pulse if the pulse is coded with a different sequence optical encryption system with a binary key code code.

Alternatively, as another example, the optical network utilizes SPE-CDMA that is based on optical frequency domain coding and decoding of ultra-short optical pulses. Each of the transmitters includes an optical source for generating the ultra-short optical pulses. The pulses comprise Fourier components whose phases are coherently related to one another.

The encoded pulse is then broadcast to all of or a plurality of the receiving systems in the network. Each receiving system is identified by a unique signature template and detects only the pulses provided with a signature that matches the particular receiving system's template. Currently, for example, the financial sectors are required by the Office of the Comptroller of Currency in the US to encrypt optical communications leaving their secure locations in the near future.

With the GbE standard on the horizon, serial datacom rates will eventually outpace the single-channel capabilities of telecom transport interfaces. Systems are needed to manage the transport of terabits of data generated from multitudes of data gathering and processing nodes delivered on demand to users in secure campuses.

The cost-effective use of existing public dark fiber and the emerging transparent reconfigurable optical add-drop multiplexer ROADM -based networks create a compelling case for photonic layer security PLS for high bandwidth needs where digital solutions, such as advanced encryption systems AESoptical encryption system with a binary key code impose a relatively high end-to-end cost.

One aspect of the present invention provides a method of encrypting and decrypting optical signals in an optical communication network. This method comprises encrypting a series of optical signals using a pair of encryptors and an encryption key to form a series of encrypted optical signals; and decrypting the series of encrypted optical signals. In accordance with this aspect of the invention, optical encryption system with a binary key code method further comprises updating the encryption key used to encrypt the series of optical signals, including using a first of the encryptors and a first encryption key to encrypt said series of optical signals; installing a new encryption key on the second of the encryptors; and when the new encryption key is installed on said second of the encryptors, switching the encrypting of the series of optical signals from the first of the encryptors to the second of the encryptors.

In one embodiment, the decrypting includes using a pair of decryptors to decrypt the series of encrypted optical signals; and the updating the encryption key includes using a first of the decryptors and the first encryption key to decrypt the series of encrypted optical signals; installing the new encryption key on the second of the decryptors; and when the new encryption key is installed on the second of the decryptors, switching the decrypting of the series of encrypted optical signals from the first of the decryptors to the second of the decryptors.

In an embodiment, the updating the encryption key further includes synchronizing the switching of the encrypting of the series of optical signals and the switching of the decrypting of the encrypted optical signals, whereby optical signals, of said series of optical signals, that are encrypted using the new encryption key are decrypted using the new encryption key. In one embodiment, the encrypting includes using an encrypt side switch to direct optical signals, of the series of optical signals, selectively to one of the first and second encryptors; and the decrypting optical encryption system with a binary key code using optical encryption system with a binary key code decrypt side switch to direct encrypted optical signals, of said series of encrypted optical signals, selectively to one of the first and second decryptors.

In an embodiment, the updating the encryption key includes encrypting the new encryption key using the first encryption key to form an encrypted key; and decrypting the encrypted key, on a receive side of the communications network, for installation in said second of the decryptors.

In this embodiment, the updating the encryption key may further include sending the encrypted key from a transmit side of the communications network to the receive side of the communications network.

In this embodiment, optical encryption system with a binary key code new encryption key may be encrypted by passing the new encryption key through said first of the encryptors, and using said first of the optical encryption system with a binary key code and the first encryption key to encrypt the new encryption key. In another aspect, the invention provides an optical communications network incorporating photon layer security. The communications network comprises a transmit side and a receive side.

The transmit side includes first and second scramblers and a transmit side switch, and the receive side includes first and second descramblers and a receive side switch. In accordance with this aspect, the first and second scramblers use encryption keys to encrypt optical signals to form encrypted optical signals, and the transmit side switch optical encryption system with a binary key code used for directing the optical signals selectively to one of the first and second scramblers.

On the receive side, the first and second descramblers use optical encryption system with a binary key code encryption keys to decrypt the encrypted optical signals, and the receive side switch is used for directing the encrypted optical signals selectively to one of the first and second descramblers. In accordance with this aspect, the communications network also comprises a control module or system for replacing the encryption keys used to encrypt and decrypt the optical signals.

This replacing optical encryption system with a binary key code done by installing new or updated encryption keys on the scramblers and descramblers, and synchronizing operation of the transmit side and receive side switches are fast enough so that all of the optical signals that are encrypted using a new or updated encryption key are decrypted using the same new or updated encryption key a number of ways may be used to instruct the switches to switch.

For example, the instructions may be part of the encryption key that is sent to the receive side, or may come from a source outside of the communications network. In one embodiment, the control module replaces one of the encryption keys with an updated encryption key by installing the updated encryption key on one of the scramblers and on one of the descramblers, controlling the transmit side switch to direct a group of the optical signals to optical encryption system with a binary key code scrambler having the updated encryption key, and controlling the transmit side switch to direct the encrypted optical signals, formed from said group of the optical signals, to the descrambler having the updated encryption key.

In an embodiment, the updated encryption key is sent from the transmit side of the optical communications network to the receive side of the optical communications network. In one embodiment, the updated encryption key itself is encrypted on the transmit side of the communications network using the previous encryption key to form an encrypted updated key, and this encrypted updated key is sent from the transmit side of the communications network to the receive side of the communications network.

In accordance with another aspect of the invention, a method is provided for encoding and transmitting optical signals in a communications network. This method comprises, on a transmit side of the communications network, modulating each signal of a set of optical signals to form a set of modulated signals, encoding the set of modulated optical signals by phase shifting at least some of the signals of said set of modulated signals to form a set of encoded modulated signals, and combining the set of encoded modulated signals to faun a composite optical signal.

This composite optical signal is encrypted by passing the composite optical signal through a first phase scrambler and using an encryption key to encrypt the composite optical signal and form an encrypted optical signal. This method further comprises, on a receive side of the communications network, decrypting the encrypted optical signal by passing the encrypted optical signal through a first phase descrambler and using the encryption key to decrypt the encrypted optical signal.

In accordance with this aspect of the invention, the method further comprises changing the encryption key used to encrypt the composite optical signal by installing a new encryption key on a second phase scrambler; and when the new encryption key is installed on the second phase scrambler, switching the composite optical signal from the first phase scrambler to the second phase scrambler, and encrypting the composite optical signal using the second phase scrambler and the new encryption key.

In one embodiment, the method further comprises changing the encryption key used to decrypt the encrypted optical signal by installing the new encryption key on a second phase descrambler; and when the new encryption key is installed on the second phase descrambler, switching the encrypted composite signal from the first phase descrambler to the second phase descrambler. In an embodiment, the encrypted optical signal is switched from the first phase descrambler to the second phase descrambler at substantially the same time as the composite optical signal is switched from the first phase scrambler to the second phase scrambler.

In one embodiment, the new encryption key is itself encrypted using the previous encryption key to form optical encryption system with a binary key code encrypted new key; and the new encrypted key is decrypted, on the receive side of the communications network, for installation in said second phase descrambler. In an embodiment, a portion of the composite optical signal may be buffered while installing the new encryption key on the second phase scrambler.

Conceptually, the coherent summation of these optically encoded tributaries can then be passed through a shared phase scrambler before exiting the secure location. The scrambler acts as the key and is a crucial element of the system security due to its large number of possible phase settings.

The authorized recipient with the correct key retrieves the ones and zeros of the several decoded signals. The unauthorized eavesdropper does not see ones and zeros to decipher the information or record the cipher text for post processing.

Archival or forensic attack is also difficult since no ones and optical encryption system with a binary key code can be seen in the tapped signal, shown at in FIG. Furthermore, spoofing of data is made considerably more challenging, since without the key, the signal received by an authorized recipient would look like that at with no ones and zeros present. As a result, the integrity of the received data is guaranteed.

In addition to illustrating an overall system architectureFIG. The optical sourcein this embodiment, comprises a phase-locked multi-wavelength laser. In accordance with this aspect of the present invention, for example, eight lines in the output spectrum comprising eight frequency bins or chips are used to communicate user data across the system The spectral content of each pulse is depicted in the frequency plots In general, the electric field m t output of the laser is a set of N equi-amplitude phase-locked laser lines:.

Equation 1 can also be expressed as:. In accordance with the sample network of FIG. In the practical sense, the total spectral width of the source's output is limited to a total spectral width of 80 GHz, which results in each pulse having a width of approximately The output signal is provided to each of the data modulators 1 through N. As such, the system preferably includes 8 users or subscribers that each provides data 1 through N that is used to respectively modulate the pulse train or output signal In the system of FIG.

The spectral content of such a signal is shown in frequency plot Other modulations, including DPSK different phase shifting keyingor the higher data content DQPSK different quertenary phase shifting keying may be used by the system Each of the modulated optical pulse signals is then fed to respective spectral phase encoders 1 through N as optical encryption system with a binary key code.

When the relative phases of the frequencies are shifted, the set of frequencies is unaltered, but their recombination results in a different temporal pattern, e. Each OCDM code is desirably defined by a unique choice of phase shifts. Preferably, a set of codes is chosen that make efficient use of the spectrum within the window, and that can also be separated from each other with acceptable error rates, even when a maximum number of codes occupy the window.

Each tributary drives its own data modulator DM and is identified by its own spectral phase encoder SPE. After combining all the data carrying codes, the optical phase of the aggregate is scrambled by The process is reversed at the receiving end, as shown in FIG. They are diagonal or monomial matrixes that increase the search space exponentially.

The relative phase setting of the scrambler and descrambler are the shared key. The functions of the encoders N and scrambler can be combined in one unit by modifying the encoder's setting. Similarly the function of the decoders N and descrambler can be combined in one unit by modifying the decoders setting. For the systemin one embodiment, the set of Hadamard codes, which are orthogonal and binary. This choice is desirable in that it can achieve relatively high spectral efficiency with minimal multi-user interference MUI.

In accordance with an aspect of the present invention, this coding schemes offers synchrony in the sense that MUI is zero at the time that the decoded signal is maximum because the signal is maximal and can be picked up by time-gating ,- N. The number of orthogonal codes is equal to the number of frequency bins, and hence, relatively high spectral efficiency is possible.

To encode data that contains a spread of frequencies, as opposed to the unmodulated pulse stream, which contains only the initial comb of frequencies produced by the MLL, it is preferable to define frequency bins around the center frequencies.

Encoding data then comprises applying the phase shift associated with a frequency to the entire bin. The output of the phase encoder is then a signal obtained by summing the phase-shifted frequency components of the modulated signal, or equivalently, by convolving the modulated optical signal at the input of the phase encoder with the inverse Fourier transform of the phase code.

Applying any of these orthogonal codes except for optical encryption system with a binary key code case of Code 1which leaves all phases unchanged results in a temporal pattern which has zero optical power at the instant in time where the initial pulse would have optical encryption system with a binary key code its maximum power.

Best binary options broker for withdrawal

  • 115 in binary option strategies 2014

    Stock option trading terms overweight

  • A block trade is how many shares in an option

    Cherrytrade binary options broker reviews

Simulator fur binare optionen euro-dollar

  • Auto binary signals honest review of shakeology

    Trading currencies to make money

  • Silver futures trading strategy

    Stock trading fees explained

  • Exchange option in flipkart

    Mb trading introducing broker

Trader konto mit binare option

44 comments Binary code digital signal processing subject

Forex trading islamabad

Published Tuesday, October 11, Cryptography could get a boost from photonic technology. The encryptions on which our finances, work and national security rely are based on one simple assumption: The public-key infrastructure developed in the s and now practically ubiquitous thanks to its incorporation into protocols, such as those used to protect web-surfing sessions, relies on the intrinsic computational difficulty of a select group of mathematical functions.

The difficulty of these operations ensures the private keys that should be used to unlock the data cannot be reverse-engineered from the encrypted text or the widely disseminated public keys that make this security strategy practical. If they work as expected, quantum computers may render many of the arithmetic techniques redundant. Is there an alternative that is less vulnerable to improvements in algorithms and changes in computer technology? One possibility is to harness the media used to convey data around the world.

Some ,km of fibre-optic cable lie under the oceans, transmitting vast quantities of information at high speed across the globe. Optical security is already a part of everyday life, from the holographic patches on CDs, DVDs and bank notes that allow us to ensure our music, movies and money are authentic, to biometric border control speeding up entry into countries. But what if the properties of propagating light could be used to provide better security for digital systems? Free-space optical security and encryption is an often-missed area of active and intense research that potentially offers just this: Using the properties of light freely propagating in air, space or a vacuum, free-space optics FSO is actually a diverse field with numerous sub-branches.

FSO and optical security are now coming together, as Sheridan describes: With optical encryption for physical storage, the information is encoded into holograms. The authenticity of the message can be validated using optical tests such as ellipsometry or speckle analysis. Security for FSO manipulates certain physical parameters of the optical waves that convey the information. These waves offer a host of hiding places for sensitive data: Called the double random phase encoding DRPE method, it converts an input laser signal, which is encoded with data using changes in phase and amplitude, into what appears to be white noise.

The technique uses phase masks - two random pattern gratings - that alter the light in both the frequency and spatial domains. The researchers calculated the probability to be one in 22,, The encrypted data bits are recorded and stored as a hologram, which can then be recorded by a CCD charge-coupled device camera and reconstructed digitally by a computer, ready to be transmitted.

When the receiver clicks on the attachment in their inbox, the image they see will be white noise. Central to decrypting the image are the phase mask keys - a full description of the two pattern gratings that encrypted the image. If the receiver has physical copies of the phase masks, they can reconstruct the image optically by simply reversing the encryption process. If the receiver instead just has the keys, they can rebuild the image digitally. The underlying approach was to produce a set of ciphertexts that, when analysed in combination, could reverse-engineer the random phase key.

The successful attack on DRPE inspired Javidi to further analyse the method, attacking the encryption himself in nine different ways. Although he proved that DRPE remains robust against brute-force attacks - that is, trying every possible key until finding the correct one - the study revealed weaknesses against chosen- and known-plaintext attacks.

In a chosen-plaintext attack, the attacker has the ability to trick a legitimate user of the system into encrypting particular images of their choosing and can also see the resulting encrypted images. Javidi found that by choosing, at most, three image pairs, an attacker can recover the two encryption keys and break the system. Worryingly, in his cryptanalysis Javidi found that attacks of this kind would only require two image pairs to break the system. The reason DRPE and many related techniques failed against these attacks boils down to one fatal flaw: Sheridan illuminates this best: There is only one possible solution that satisfies all the equations and so, although it might be numerically difficult or tedious [to solve], in general it is possible to find the one good solution, or at least get close to it.

Far from discouraging the community though, this crucial weakness has stimulated ingenious directions in research that can deal with cunning attack strategies. The key problem is one caused by the greater predictability of linear systems.

He and others are now looking to exploit non-linearity in optical processes. Carnicer and Javidi have joined forces to lead the way in advancing one research direction that could overcome the effects of linearity: Importantly, this is a nonlinear transformation of the data. However, since photon counting is performed on the amplitude of the encrypted message, information is lost, so that when decrypting the message the receiver obtains a noisy, unrecognisable image.

Importantly, though, only the amplitude information is modified. The photon-limited encrypted image can be verified from phase information using nonlinear filters. This technique could have important uses in object identification, particularly hardware security.

For example, counterfeit integrated circuits ICs are a growing problem. In , two nuclear operators in the US reported they had unwittingly purchased counterfeit parts for replacements to their control systems. Reported counterfeit parts incidents quadrupled between and Half of all manufacturers have, at some point, encountered bogus components. Adding an optical phase tag to a genuine IC means its authenticity can be confirmed by the eventual buyer simply by illuminating the tag with a laser and capturing the resulting speckle signature with a CCD.

One way of introducing nonlinearity in optical security that Situ is exploring is to change the way light propagates through the encryption device. With a photorefractive crystal placed into a standard DRPE system, laser light can propagate nonlinearly. Other, more speculative possibilities are also being explored.

For instance, the nanoworld offers a raft of potential new ways to hide information. One example is in optical artefact metrics. Artefact metrics use the intrinsic, complicated and hopefully unique characteristics of a physical object for authentication.

A sheet of paper, for example, scanned at the micro-level will have a unique pattern of random, naturally occurring texture imperfections that can be used to watermark or fingerprint a document. Although this pattern is unique, it is only due to current technological limitations that it cannot be copied by a skilled forger. Such techniques may be the ultimate in anti-counterfeiting.

Unlike lone-wolf hackers infiltrating government and corporate digital systems from their bedrooms, optical cryptanalysts work in collaboration and simulate attacks on security systems in the lab. Then we send something into the system and get something out. Using the input and output data, cryptanalysts attempt to establish a connection, and develop suitable computational algorithms to deduce the keys.

Professor John Sheridan from University College Dublin, who has also mounted successful attacks on advanced DRPE-based systems, notes a dearth of people willing to attack optical security systems: This might be the case for several reasons: So while increasingly complex systems are being designed, there is still no way of telling how vulnerable they are to attacks - always leaving a sliver of doubt in the mind of even the most confident cryptographer.

Brute-force attack - as the name suggests, a brute-force attack involves trying every possible combination of data in order to find the key that decrypts an encrypted message. It is usually a last resort and usually not regarded as practical because modern encryptions have huge key spaces that would take hundreds or thousands of years to crack with this method. This is a weak attack because the attacker has little to work with.

Many classic ciphers are susceptible to this type of attack, as were older versions of encrypted ZIP files. Eve registers and starts encrypting chosen files and looks at the resulting ciphertext. The Allies mounted such an attack to decipher messages from the Enigma machine during World War Two, but could only do so once they had captured one.

Chosen-ciphertext attack - including the lunchtime attack and the adaptive chosen-ciphertext attack. This kind of attack is impractical in many situations, but is also the strongest of the above methods. Side-channel attack - unlike other methods, which find weaknesses in the cryptographic algorithms or use brute force, side-channel attacks exploit weaknesses in the physical implementation of the security. Sound, electromagnetic leaks, power use and many more can be exploited to break the system.

RFID tags, smart cards and even PCs have been shown in the past to be vulnerable to attacks on hardware leakage. Our sites use cookies to support some functionality, and to collect anonymous user data. Welcome Your IET account. Photonics steps in to solve security issues with cryptography. Cyber-gang suspects arrested over billion-euro ATM hacks. British cyber-security sector propped up by government drive to win foreign business.

Many off-the-shelf IoT devices require no effort to hack, study shows. Social media giants have made no counter-terrorist referrals to police, top officer reveals.

Quantum technology research to prevent hackers hijacking autonomous vehicles. Camera that mimics butterfly eyes aids tumour removal in cancer patients. Virgin Galactic completes SpaceShipTwo test flight three years after fatal accident.

Facebook requested that hospitals share patient data, says CNBC. Wearable device enables control over computer with thoughts. Facebook one of 30 companies under investigation after CA fallout. Learn more about IET cookies and how to control them.