Lig ht Keys
a journey to quantum communication volume 1
Milica Prokic
Lig ht Keys
Credits Written by Milica Prokic Based on the stories by John Rarity, Henry Semenenko, Imad Faruque et al Artwork by Milica Prokic Layout and Graphic Design by Neil Simmons Storyboards and sketches by Milica Prokic and Holly Caskie Featuring the stunning artworks by India Chubbs, Bily George and Ben Jordan (Knowle West Media Centre) & Sue Keefe (Beehive Community Centre)
Introduction Our story is about the journey of cryptography, mathematics, physics and optics through time, from the first recorded cryptography device in EuropeSKYTALE, notably used in ancient Sparta, to today's quantum informatio n hubs and research centres. From ancient Sparta, Al‑Khwarizmi's Baghdad, Alhazen's Cairo and Ibn Sina's Shah-e Rey, through the World War Two Resistance movements, with a pit-stop at Massachusetts Institute of technology, we arrive at 2019. There, we look at what the development of quantum cryptography, pondering how to go about it.
chapter 1: The Classical Past skytale
c. 7th century BC
Is lamic Golden Age
8th to 10th century AD
modern times encryption one time pad
since 1910s
public key cryptosystem (RSA) chapter 2: the Quantum Present
1970s
chapter 1:
The Classical Past
Skytale (rhymes approximately with Italy, Greek: σκυτάλη: baton)
is a tool used to perform a transpositio n cypher consisting of a cylinder with a strip of parchment wound around it on which a message is written. The ancient Greeks, Spartans in particular, are said to have used this cipher to communicate during military campaigns.
A description of how skytale operated is first known from Plutarch (50-120 AD): The dispatch-scroll is of the following character. When the ephors send out an admiral or a general, they make two round pieces of wood exactly alike in length and thickness, so that each corresponds to the other in its dimensions, and keep one themselves, while they give the other to their envoy. These pieces of wood they call skytale. Whenever, then, they wish to send some secret and important message, they make a scroll of parchment long and narrow, like a leathern strap, and wind it round their skytale, leaving no vacant space thereon, but covering its surface all round with the parchment. After doing this, they write what they wish on the parchment, just as it lies wrapped about the scytale; and when they have written their message, they take the parchment off and send it, without the piece of wood, to the commander. He, when he has received it, cannot otherwise get any meaning out of it,--since the letters have no connection, but are disarranged,-unless he takes his own scytale and winds the strip of parchment about it, so that, when its spiral course is restored perfectly, and that which follows is joined to that which precedes, he reads around the staff, and so discovers the continuity of the message. And the parchment, like the staff, is called skytale, as the thing measured bears the name of the measure.
Plutarch, Lives (Lysander 19)
Sparta, Lakedaimon, 459 BC
We need to take one of them with us. Choose.
understand: this is difficult for me
You understand the necessity of this, Gorgo.
They intercepted our skytale. They know our system. We need to use the twins. One of the two needs to come with us, the other one has to stay here for now.
very well
The other should go to the oracle. Ten nights from now.
and so it was decided: instead of the skytale staff, the rig ht arms of the identical twins were to be used. and instead of the parchment, as we shall discover, magic interventions of certain deities...
10 nights later...
wake up.
time for you to go.
to meet her. through the woods
to the crossroads.
At the crossroads, approach the keykeeper.
To take her key from the thread of light
you must first please her familiars...
...with an offering
with the dagger from her fifth hand, cut through the thread, swiftly.
Hekate is a goddess in ancient Greek mythology most often shown holding a pair of torches and a key. She shows herself to mortals in triple form. She was variously associated with crossroads, entrance-ways, light, magic, witchcraft, knowledge of herbs and poisonous plants. In some stories her consort is Hermes the trickster, the shrewd one, the messenger god, wings on his helm, swift on his feet.
carry on. through the woods. to meet him.
the shrewd, winged one
Place the key in his hand and watch the magic unfold.
as the key...
turns into his staff.
and the message scrolls come alive.
let it coil around your arm.
go ahead, be afraid and bewildered.
Now whisper these words to the living scroll
Their arrows will darken...
and send it off to your twin.
it's our message. no! leave it be!
If we only knew how many are coming our way, and from which side
please say you' have a message for me, child.
stand still. the letters are appearing
Their arrows will darken the sky Use land to advantage
And so, thanks to the message of the shrewd wing‑footed god, the key-giver goddess and the twin‑human skytale, the Spartans had a glimmer of hope that the impending battle would turn to their favour.
Baghdad, 9th century AD
Is lamic Golden Age the period between the 8th and the 14th centuries in the Middle East, when the arts and the sciences flouris hed under the protection of various caliphates, is known as the Islamic Golden Age. One of the art and science centres of that time was the magnificent city of Baghdad.
You say, ten less a thing, multiplie d by itself, is a hundred plus a square less twenty things, and this is equal to eighty-one things.
Extract the root from this; it is fortynine and a half. Subtract this from the moiety of the roots, which is fifty and a half. There remains one, and this is one of the two parts
Separate the twenty things from a hundred and a square, and add them to eighty-one. It will then be a hundred plus a square, which is equal to a hundred and one roots. Halve the roots; the moiety is fifty and a half.
Multiply this by itself, it is two thousand five hundred and fifty and a quarter. Subtract from this one hundred; the remainder is two thousand four hundred and fifty and a quarter.
There must be a better way to say all this! Baghdad was also home to al-khwarizmi, 'the father of algebra'. Thanks to this great Islamic scholar, among a few others, we are now able to express mathematical equations precisely- in numbers, rather than descriptively- in words.
From his latinised name (Algoritmi) the word ALGORITHM was derived. through his work he had set the foundations on which the modern mathematics was built, which is the language of physics.
The City of Cairo, 1015 AD in ! els ees rav line it t aight str
The sage has lost his mind. they keep him under lock and key
Lost mind?!?! ...oh NoNoNoNoNo... just left it at home! Here, have a look through my prism!
Move it now.
back to the tower with you, old man.
My work can continue.
Now when they're gone...
Hasan Ibn al-Haytham latinised Alhazen (c.965 - c.1040), was an Arab mathematic ian, astronomer and physic ist of the Islamic Golden Age. Sometimes referred to as The Forefather of Modern Optics, he made significant contributions to the field. These include some of the first experiments with camera obscura, and other experim ents exploring visual perception. His most influential work is 'The Book of Optics', written between 1011 and 1021. Anecdotally he wrote it while feigning madness.
we leave Alkazen in his tower as He mutters to himself - well the Greeks, they thought that we shine the light from our eyes but I should say, I should say - quite the opposite is true, the light in fact comes into our eyes.
Shahr-e-Ray, Persia 1025 AD
if the perception of light...
...is due to the emission of some sort of particles by a luminous source...
...then the speed of light...
...must be finite.
Avicenna also known as ibn sina or abu ali sina; Persian ( ;انیس نباc. 980-June 1037) was a Persian polymath who is regarded as one of the most significant physicians, astronomers, thinkers and writers of the Is lamic Golden Age. Avicenna's importance to our story comes from his research in physics and astronomy. His pondering on the structure and the behaviour of light had, very early on, brought him to the conclusion that light is made out of partic les, and that it therefore moves in a certain way. HIs hypothesis on the finite speed of light is now a proven axio m.
Artwork by the very creative India Chubbs
'All the 50 years of concious brooding have brought me no closer to the question - What are light quanta? Of course today every rascal thinks he knows the answer, but he's deluding himself.' Albert Einstein, 1951
Modern Times Encryption The One Time Pad
artwork by one very talented Benjamin Jordan
Boston, MA, 2001.
my training jumps had all been from a standing position in the door of a plane. For reasons I don't understand even today the thought
From 'Beacons in The Night' a memoir by Frank Lindsay of dropping passively through a hole into the night was infinitely more disagreeable than jumping from an open door.
there! The signal! Jump!
1944, Yugoslav airspace
May 1944, near Slovenian border, Yugoslav occupied territory
...and this is how i met the 14th Yugoslav Partisan Division. Francis Lindsay, OSS, Allied SPecial Forces.
password.
...and even the local priest
the antifascist people's guerilla that included youth, women, children
that winter was tough for the group, moving through the mountains, in blizzards, on foot.
I was sent to their aid some six months after.
we were sent to provide help for the partisans in food, logistics, and intelligence. we were given a radio station system and a ONE-TIME PAD by the British S.O.E., the Special Operations Executive... ...also known as the 'Baker Street Irregulars'. in Yugoslavia they were represented by Fitzroy Mclean
to decipher the message, the base radio station would use the second copy of the same page of random letters in the duplicate of our one-time pad. for example,the first letter of the enciphered message, O, would be written above letter K, the corresponding letter on the one-time pad. Using another copy on our look-up table, the cipher clerk would end the corresponding column.
at the intersection of the column and the line, the cryptographer would find the first letter of the original word: 'TONight'.
hid den in plain sig ht public key encryptio n
artwork by
RSA is an algorithm used by modern computers to encrypt and decrypt messages. It is an asymmetric cryptographic algorithm. Asymmetric means that there are two different keys. This is also called public key cryptography, because one of the keys can be given to anyone. The other key must be kept private. In the late 1970s, computer scientists Rivest and Shamir with number theorist Adleman devised the public key encryption code that bears their initials (and that has been in use ever since to secure electronic transactions).
Rivest
for several months; Shamir and Rivest would toy with the problem over dinners at local restaurants, Public key cryptosystems were even the topic of conversation at a student's Passover seder in 1977. Around midnight the evening of the seder, Rivest called Adleman with a new idea. It was immediately clear to Adleman that the idea was a good one. RSA is one of the first public-key cryptosystems and is widely used for secure data transmission. In such a cryptosystem, the encryption key is public and it is different from the decryption key which is kept secret.
In April 1977, they spent Passover drinking a good deal of wine. Rivest, unable to sleep spent the rest of the night formalizing his idea, he had much of the paper ready by daybreak. The algorithm is now known as RSA the initials of their surnames.
adleman
shamir
Quite abstractly, you have some secret you want to get through, and some public thing that takes your secret message and scrambles it, unless you have the private keythe trick which un-scrambles it.
Thus it is hidden in plain sight, once the message is scrambled, it is open for everyone to see, one- how it's scrambled, and two- what the scrambled bit was.
Algorithm is a set of steps expressed in numbers. It's sort of like a recipe. Everyone who knows the steps also knows exactly how the recipe works, knows the numbers, knows how to send this secret message. And then that message gets privately scrambled, just like adding a secret ingredient to the recipe in the privacy of your own kitchen. And the final product can be sent across the public. The receiver of the message knows the secret of the reverse steps of this message, this 'scrambled' recipe. Only they know it.
It's an encrypted communication between the two parties which is visible, but no interpretable across the public. in other words,
no one knows how to unscramble it unless they have this private key.
she puts it back, shuffles the deck
It's kind of like a card trick
Alice picked a card out. She's the only one who saw it.
but You don't know what's her card
unless you're Bob the magician, who knows the trick of finding it is this your card?
Everyone saw her do it the audience knows the public key alice knows the message which is the act of shuffling
bob knows the private key, which is the trick (perhaps the card is marked?)
which is the chosen card. The public key is how the deck was shuffled.
now ALICE, she could be...
hence the term 'asymmetric cryptographic algorithm'.
so each party has a different piece of knowledge
...anyone who decides to send the message
artwork by the super- artsy Billy George
chapter2:
The quantum Present
so the history of cryptography concerns the inventio n of encryptio n algorithms (and the inventio n of decrypting methods - more about that in the next episode) the present (and the future) of cryptography had moved, and continues to move toward quantum. Quantum concerns the smallest bits of the universe we can measure, and here it refers to a photon, i.e., a quantum of light. Photons vibrate as they move. Information can be encoded using the angle of photon vibrations and used to send or share secret keys between two users. People trying to listen in and intercept the link produce errors that can be detected to reveal them. and this is where our story continues...
Quantum In The Crowd
'Keys are long random strings of numbers that both sender and recipie nt of a coded message must possess. But they are not usually sent electronically because anyone could decode the message if the key is in tercepted.
Quantum cryptography, named because it exploits the unusual properties of quantum mechanics, allows these keys to be encoded as particles - photons - of laser light and sent along optical fibres or through air. Intercepting and reading the message changes the 'quantum state' of the photons
2016 Tunisia,World Telecommunication Standardization Assembly
Cyber-security will only be in the hands of those who can afford it if we don't get to grips with quantum computing technology.
Jaya Baloo addresses the delegates
Bristol. UK, later that year
o n ly
the University's School of Physics wishes to congradulate Dr Aabha Faruque, for becoming the youngest PhD in quantum photonics in the history of this school.
in th
o d n a eh
f t h ose
...
i f w e d o n ' t g e t to g r i ps . . .
o n ly i n t h e
later that night
congr at doc s
hand
. . . e s of tho
Local Quantum security start-up raises over 2 million in investment Bristol, UK 2019
hermes
quantum
Quantum computers, such as those currently developed by several corporate giants, promise to create a new generation of supercomputers with computing power that poses a critical threat to current cyber security encryption. To counter this threat,the Hermes team have developed one of the world's first integrated quantum secured encryption technologies capable of protecting against this vulnerability at scale.
Corporations and government initiatives back quantum-secure communications start-up, Hermes Quantum Security. This is developing a range of future-proof, cost-effective technologies for quantumsecured communications that have the potential to improve the secure transmission of information such as banking details and medical records.
This new suite of secure communications systems has proven robust against both conventional and quantum threats, and the Hermes team aims to use these systems to boost security in defence, telecoms and critical infrastructure, with end-users in finance, governments and data centres. Hermes Quantum's co-founder, Aabha Faruque said: “Our aim is to become the digital security of the future, protecting our digital information and critical infrastructure in the 21st century and beyond.”
but...
are all like, entangled?
is it as scary as the nuke? what does this really imply... what if ronald mcdonald gets hold of it?! ...in terms of our everyday life?
...will it help me find a date?
Cyber-security will only be in the hands of those who can afford it if we don't get to grips with quantum computing technology right? RIGHT?!
what's a photon?
is my cat a zombie?
AcknowledgemEnts Working on this volume has been a joyful, collaborative venture. Our acknowledgements represent a diverse list of people, aged 7 to 75+, from both inside and outside the Quantum Engineering Technology (QET) Labs team. All involved have helped shape our conversation about light, its particles, and the past, present and future of quantum cryptography and communication. First and foremost, our thanks go to the creative Bristol community. To Dot Baker and the young people from the Knowle West Media Centre for hosting and taking part in our quantum research and art sessions; special thanks to India Chubbs, Ben Jordan and Billy George for their artworks featured in this volume. To the creative and curious Fani Golemi, who connected us with the Beehive Centre - a delig htful community of Bristolians aged 55+. Special thanks to group member Sue Keefe, whose artwork also features here. To Rita Gupta from the North Bristol Community Project, who provid ed generous support and endorsement, and to Hamilton House for hosting our exhibition and connecting us with the wider community. Thank you to QET Labs members Dr Imad Faruque, Alexandra Moylett, Dr Alasdair Price, Dr Dondu Sahin, Dr Philip Sibson, Dr Gerardo Villarreal Garcia and Henry Semenenko from the Quantum Engineering Centre for Doctoral Train ing for developing and proofreading our story, and for
running our workshops and demos. Extra specia l thanks to the talented mover and shaker Holly Caskie, for making all the organisational things happen and sketching out some of the best-looking pages in here. A very special thank you to Dr Caroline Clark, who facilitated and whole-heartedly supported this project from the beginning, making sure it came to life. Thank you to Mireia Bes and Ellie Cripps from the University of Bristol Centre for Public Engagement for believing in the project and helping us apply for funding. Of course, thank you to the University's Research and Enterprise Development team (RED) for granting us funding through an EPSRC Impact Acceleration Account Award. Thanks to Neil Sim mons, who worked on the lettering, layout, graphic desig n, and turning many pages into one polished volume. Last but not the least thank you, dear reader, for engaging with this work. In doing so you are helping us to reach as many curious minds as possible. Dr Milica Prokic , Professor John Rarity & QET Labs (University of Bristol)
