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LocalBitcoins, a leading peer to peer (P2P) Bitcoin exchange, notes that with the advent of quantum computing, there have been concerns that this new technology could be a threat to existing online protocols. Some experts claim that powerful quantum computers might become a legitimate threat to the security of Bitcoin (BTC) and the current encryption algorithms that it uses.

According to LocalBitcoins:

While the threat of quantum computing to Bitcoin is to be taken seriously, experts believe that Bitcoin [and other cryptocurrencies] have time to adapt to the quantum age without compromising [their] security in the process.

As explained in a blog post by LocalBitcoins, Bitcoin or BTC and its blockchain-based network is secured by cryptographic algorithms, which is why its called a cryptocurrency. Cryptography allows developers to protect certain sensitive data and communication on a platform so that only the parties authorized to view the information can access it. The LocalBitcoins team notes that cryptography uses several different algorithms, and Bitcoin depends on them to function properly.

At present, these algorithms are almost impossible to break, but quantum computers may spell trouble to these algorithms in various ways, according to LocalBitcoins.

They explain that the idea or concept behind quantum computing is to go beyond the power of traditional computers by leveraging quantum mechanics, a field in physics that describes behaviors on a subatomic scale. They also noted that when unobserved, subatomic particles can exist in multiple places at once, however, when [they have been] detected, they collapse into a single point in space-time.

They further explain:

Traditional computers operate with bits which encode either a 0 or a 1, while quantum computers use quantum bits, or qubits, which can be both a 0 or a 1 at the same time. This phenomenon is known as superposition which allows a huge amount of calculations to be carried out simultaneously.

They continued:

Bitcoins algorithm most at risk from quantum computing is its signature algorithm that uses ECDSA (Elliptic Curve Digital Signature Algorithm) [which] is used to generate the public/private key pair to sign Bitcoin transactions securely (sending and receiving coins). ECDSA uses asymmetric encryption, and the reason for it being secure comes from the need to factor multiple large prime numbers to break the algorithm. Breaking ECDSA and deriving a private key from a public key using current computers would take such an astronomical amount of time that it wouldnt even be realistic to try it out.

But with quantum computers that support parallel calculation, this same process can be carried out a lot more efficiently, and multiple types of attacks then become possible, the LocalBitcoins team noted.

They explained that the first one of these potential attacks aims to target re-used addresses. When a transaction is performed, your public key becomes visible on the blockchain or a distributed ledger technology (DLT) network. The LocalBitcoins team adds that knowing your public key, an attacker whos using quantum computers may then use your public key to derive your private key. After theyve determined what your private key might be, they can begin signing transactions on your behalf which means they can also spend your Bitcoins or any other cryptocurrency.

LocalBitcoins clarifies that addresses that have not been used to send transactions are quantum-safe because quantum computers cant read their public key.

LocalBitcoins further noted that another possible attack is the double-spend attack. This measures how fast a quantum computer can derive your private key from the already visible public key. They pointed out that if an attacker can do this before your transaction is confirmed multiple times in a block, you are essentially both trying to spend the same bitcoin, and the attacker wins.

They also mentioned:

Bitcoins hashing function used in the block creation is even more robust in the face of a quantum threat than its signature algorithm. The algorithm Bitcoin uses in its mining process is called SHA-256. When a miner solves a block and receives the right to add it to the blockchain, that miners transactions become confirmed, and part of the ledger.

They further explained:

To solve a block, a miner needs to guess a nonce, or a value that after a hash is applied, results in a number that has a certain number of leading zeroes. As a miner, you cant start from a valid result and then generate the correct nonce from it. You have to randomly guess it. This takes a lot of computing power and is behind the proof-of-work securing Bitcoins network. If the SHA-256 was broken somehow, an attacker could mine new blocks at will and earn all Bitcoin block rewards.

LocalBitcoins notes that existing quantum computers are only operated in labs and still appear to be a long way from becoming a legitimate threat to Bitcoin and other cryptocurrencies. According to estimates, a quantum computer of around 4000 qubits would be required to break Bitcoins code, while the most powerful quantum computers available right now operate with only about 50 qubits.

Industry experts predict that quantum computing machines may begin to break binary based encryption algorithms within the next decade unless theres an unexpected mathematical or physical breakthrough before that.

The LocalBitcoins team added:

When the quantum threat becomes more imminent, cryptography will have moved to more quantum-proof algorithms. In the process, Bitcoins algorithms would have become quantum-resistant as well. This can be achieved by hard-forking (backwards incompatible upgrade) the Bitcoin blockchain by consensus among the Bitcoin nodes, so it will be secure from quantum attacks.

They continued:

As long as multiple users have access to a quantum computer, no single entity will be able to gain dominance over Bitcoin mining. Perhaps in the future Bitcoins blockchain will be operated completely by nodes running on quantum computers.

Original post:

Threat of Quantum Computing to Bitcoin Should be Taken Seriously, But theres Enough Time to Upgrade Current Security Systems, Experts Claim -...

Walk into a quantum lab where scientists trap ions, and you'll find benchtops full of mirrors and lenses, all focusing lasers to hit an ion trapped in place above a chip. By using lasers to control ions, scientists have learned to harness ions as quantum bits, or qubits, the basic unit of data in a quantum computer. But this laser setup is holding research back making it difficult to experiment with more than a few ions and to take these systems out of the lab for real use.

Now, MIT Lincoln Laboratory researchers have developed a compact way to deliver laser light to trapped ions. In a recent paper published in Nature, the researchers describe a fiber-optic block that plugs into the ion-trap chip, coupling light to optical waveguides fabricated in the chip itself. Through these waveguides, multiple wavelengths of light can be routed through the chip and released to hit the ions above it.

It's clear to many people in the field that the conventional approach, using free-space optics such as mirrors and lenses, will only go so far, says Jeremy Sage, an author on the paper and senior staff in Lincoln Laboratory's Quantum Information and Integrated Nanosystems Group. If the light instead is brought onto the chip, it can be directed around to the many locations where it needs to be. The integrated delivery of many wavelengths may lead to a very scalable and portable platform. We're showing for the first time that it can be done.

Multiple colors

Computing with trapped ions requires precisely controlling each ion independently. Free-space optics have worked well when controlling a few ions in a short one-dimensional chain. But hitting a single ion among a larger or two-dimensional cluster, without hitting its neighbors, is extremely difficult. When imagining a practical quantum computer requiring thousands of ions, this task of laser control seems impractical.

That looming problem led researchers to find another way. In 2016, Lincoln Laboratory and MIT researchers demonstrated a new chip with built-in optics. They focused a red laser onto the chip, where waveguides on the chip routed the light to a grating coupler, a kind of rumble strip to stop the light and direct it up to the ion.

Red light is crucial for doing a fundamental operation called a quantum gate, which the team performed in that first demonstration. But up to six different-colored lasers are needed to do everything required for quantum computation: prepare the ion, cool it down, read out its energy state, and perform quantum gates. With this latest chip, the team has extended their proof of principle to the rest of these required wavelengths, from violet to the near-infrared.

With these wavelengths, we were able to perform the fundamental set of operations that you need to be able to control trapped ions, says John Chiaverini, also an author on the paper. The one operation they didn't perform, a two-qubit gate, was demonstrated by a team at ETH Zrich by using a chip similar to the 2016 work, and is described in a paper in the same Nature issue. This work, paired together with ours, shows that you have all the things you need to start building larger trapped-ion arrays, Chiaverini adds.

Fiber optics

To make the leap from one to multiple wavelengths, the team engineered a method to bond a fiber-optic block directly to the side of the chip. The block consists of four optical fibers, each one specific to a certain range of wavelengths. These fibers line up with a corresponding waveguide patterned directly onto the chip.

Getting the fiber block array aligned to the waveguides on the chip and applying the epoxy felt like performing surgery. It was a very delicate process. We had about half a micronof tolerance and it needed to survive cooldown to4 kelvins, says Robert Niffenegger, who led the experiments and is first author on the paper.

On top of the waveguides sits a layer of glass. On top of the glass are metal electrodes, which produce electric fields that hold the ion in place; holes are cut out of the metal over the grating couplers where the light is released. The entire device was fabricated in the Microelectronics Laboratory at Lincoln Laboratory.

Designing waveguides that could deliver the light to the ions with low loss, avoiding absorption or scattering, was a challenge, as loss tends to increase with bluer wavelengths. It was a process of developing materials, patterning the waveguides, testing them, measuring performance, and trying again. We also had to make sure the materials of the waveguides worked not only with the necessary wavelengths of light, but also that they didn't interfere with the metal electrodes that trap the ion, Sage says.

Scalable and portable

The team is now looking forward to what they can do with this fully light-integrated chip. For one, make more, Niffenegger says. Tiling these chips into an array could bring together many more ions, each able to be controlled precisely, opening the door to more powerful quantum computers.

Daniel Slichter, a physicist at the National Institute of Standards and Technology who was not involved in this research, says, This readily scalable technology will enable complex systems with many laser beams for parallel operations, all automatically aligned and robust to vibrations and environmental conditions, and will in my view be crucial for realizing trapped ion quantum processors with thousands of qubits.

An advantage of this laser-integrated chip is that it's inherently resistant to vibrations. With external lasers, any vibration to the laser would cause it to miss the ion, as would any vibrations to the chip. Now that the laser beams and chip are coupled together, the effects of vibrations are effectively nullified.

This stability is important for the ions to sustain coherence, or to operate as qubits long enough to compute with them. It's also important if trapped-ion sensors are to become portable. Atomic clocks, for example, that are based on trapped ions could keep time much more precisely than today's standard, and could be used to improve the accuracy of GPS, which relies on the synchronization of atomic clocks carried on satellites.

We view this work as an example of bridging science and engineering, that delivers a true advantage to both academia and industry, Sage says. Bridging this gap is the goal of the MIT Center for Quantum Engineering, where Sage is a principal investigator.We need quantum technology to be robust, deliverable, and user-friendly, for people to use who aren't PhDs in quantum physics, Sage says.

Simultaneously, the team hopes that this device can help push academic research. We want other research institutes to use this platform so that they can focus on other challenges like programming and running algorithms with trapped ions on this platform, for example. We see it opening the door to further exploration of quantum physics, Chiaverini says.

Originally posted here:

Lighting up the ion trap - MIT News

When Thomas Searles was assigned a book report in the first grade, he initially had trouble choosing a topic. He really didnt like fiction books. After a bit of indecision, he chose to write his report on a book about Black astronauts. Though he didnt realize it at the time, his journey to becoming a physicist at MIT had just begun.

I looked in the book, and there was Ronald E. McNair, who happens to be an MIT alum, randomly; he got his PhD here, Searles says. And it said that he was a laser physicist. So, I said, Well, that's what I'm going to be, because I want to be an astronaut.

Searles is now a member of the 2020-21 Martin Luther King (MLK) Visiting Professors and Scholars Program cohort at MIT. Since 1995, the MLK Scholars Program has brought in a total of 67 visiting professors and 21 visiting scholars from across all academic disciplines. Individuals of any underrepresented minority group are eligible to apply, and scholars are selected for their contributions both to their fields and their potential contributions to MIT.

It's something that was always on my radar as a young Black scientist, Searles said. It was something that was on my five- to 10-year plan.

Searles is currently an associate professor in the Department of Physics at Howard University, a historically Black college and university (HBCU) located in Washington. There, he established a new research program in applied and materials physics. He is also the director of a new academic partnership between IBM and 13 other HBCUs called the IBM-HBCU Quantum Center.

Searles research career began as an undergraduate in mathematics and physics at Morehouse College, a HBCU in Atlanta. Before graduating in 2005, he worked in an optics lab, examining the properties of light and its interactions with matter.

A lot of us had an interest in optics, because that was the only experimental lab that we had at Morehouse at the time, Searles says. So naturally, I applied to graduate schools that were optics-related.

That interest led him to pursue his PhD in applied physics in the Department of Electrical and Computer Engineering at Rice University in Houston, Texas, from which he graduated. Before graduating in 2011, he studied light-matter interactions, and completed a thesis about the magneto-optical properties of carbon nanotubes, tiny cylinders comprised of a single layer of carbon atoms. Carbon nanotubes are extremely strong, lightweight, and electrically conductive, making them promising for a variety of applications.

In 2015, Searles started at Howard University. I wanted to go back and work at an HBCU. I thought of my experience working in the Morehouse optics lab and how they kind of shaped my experience, Searles says. So then I was like, What can I do that's different from everyone else that will also provide opportunities to a lot of Black students? So, I set out to start a terahertz experimental lab, knowing that it was going to be difficult. And it was difficult. But we were able to do it.

In the terahertz spectroscopy lab at Howard University, researchers work with matter that has a large wavelength, and a frequency between several hundred gigahertz and several terahertz. During the first so-called quantum age in the mid-1900s, silicon was the new, exciting material used to develop transistors. Now, researchers in fields like chemistry and physics are on the hunt for the next material to be a platform for a new generation of quantum technologies.

The primary goal is to study materials for new computers, making them either safer, faster, or more secure, Searles says. This whole idea of quantum computing is what we're focusing our lab on, moving towards this idea of quantum advantage.

Quantum computing relies upon the use of quantum materials which have unique electronic and magnetic properties to build faster, stronger, and more powerful computers. Such machines are likely to provide this quantum advantage for new developments in medicine, science, finance, chemistry, and many other fields.

In 2016, Searles met MIT associate professor of physics and Mitsui Career Development Professor in Contemporary Technology Joseph Checkelsky at an event through the National Science Foundation Center for Integrated Quantum Materials.

The idea was to try to find people that we wanted to collaborate and work with, Checkelsky says. And I think I even wrote down in my notepad Thomas' name and put a big underline that I should work with this guy. Searles says the best thing that can ever happen to a spectroscopist like himself is to find a crystal-growth person that provides samples, who you also really vibe with and like as a person. And that person for me has been Joe. The two have been collaborating ever since.

Checkelskys lab works to discover new crystalline materials that enable quantum phenomena. For instance, one material that has previously been of interest to Checkelsky is a kagome crystal lattice, a 2D arrangement of iron and tin molecules. Both Checkelsky and Searles are interested in applying a branch of mathematics called topology to solids, particularly semimetals.

One of the roles Thomas plays is to examine the optical properties of these new systems to understand how light interacts with quantum materials, Checkelsky says. Its not only fundamentally important, it can also be the bridge that connects to new technologies that interfaces light with quantum science.

Searles expertise on the optics side of the research enables him to identify which materials are ideal for further study, while Checkelskys group is able to synthesize materials with certain properties of interest.

It's a cycle of innovation where his lab knows how it can be tested and my lab knows how to generate the material, Checkelsky says. Each time we get through the cycle is another step toward answering questions in fundamental science that can also bring us to new platforms for quantum technology.

Checkelsky nominated Searles for the MLK Scholars Program in hopes of further expanding their academic partnership. He now serves as Searles host researcher through the program.

I hope to extend my collaboration with Joe to not only [explore] this condensed matter, experimental side of my group, but to expand this into Lincoln Laboratory and the quantum information portion that MIT has, Searles says. I think that's critical, research-wise.

In addition to their research goals, Searles and Checkelsky are excited to strengthen the general connection between MIT and Howard.

I think there are opportunities for Thomas to see, for example, the graduate school process in our department, Checkelsky says. Along the same lines, it is a great opportunity for MIT and our department to learn more how to connect to the people and science within HBCUs. It is a great chance for information to flow both ways.

Searles also hopes to encourage more HBCU students to pursue graduate study at MIT. The goal of increasing the number of qualified applicants [from HBCUs] I think that's something that I can measure metrically from the first year, Searles says. And if there's anything that I can do to help with that number, I think that would be awesome.

See the rest here:

For Thomas Searles, a passion for people and science at HBCUs and MIT - MIT News