How does public-key cryptography work? What is a private key and a public key? Why is asymmetric encryption different from symmetric encryption? I'll explain all of these in plain English!
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Views: 193690
Simply Explained - Savjee

Dr. Tomoyuki Yamakami was invited to the Instituto Superior Técnico (IST), University of Lisbon in Lisbon, Portugal to deliver a public talk regarding quantum complexity theory and cryptography on March 15, 2013.
Speaker: Tomoyuki Yamakami
Language: English
Title: Quantum Hardcores and Quantum Public-Key Cryptosystems

Views: 34
Tomoyuki Yamakami

Modern day encryption is performed in two different ways. Check out http://YouTube.com/ITFreeTraining or http://itfreetraining.com for more of our always free training videos. Using the same key or using a pair of keys called the public and private keys. This video looks at how these systems work and how they can be used together to perform encryption.
Download the PDF handout
http://itfreetraining.com/Handouts/Ce...
Encryption Types
Encryption is the process of scrambling data so it cannot be read without a decryption key. Encryption prevents data being read by a 3rd party if it is intercepted by a 3rd party. The two encryption methods that are used today are symmetric and public key encryption.
Symmetric Key
Symmetric key encryption uses the same key to encrypt data as decrypt data. This is generally quite fast when compared with public key encryption. In order to protect the data, the key needs to be secured. If a 3rd party was able to gain access to the key, they could decrypt any data that was encrypt with that data. For this reason, a secure channel is required to transfer the key if you need to transfer data between two points. For example, if you encrypted data on a CD and mail it to another party, the key must also be transferred to the second party so that they can decrypt the data. This is often done using e-mail or the telephone. In a lot of cases, sending the data using one method and the key using another method is enough to protect the data as an attacker would need to get both in order to decrypt the data.
Public Key Encryption
This method of encryption uses two keys. One key is used to encrypt data and the other key is used to decrypt data. The advantage of this is that the public key can be downloaded by anyone. Anyone with the public key can encrypt data that can only be decrypted using a private key. This means the public key does not need to be secured. The private key does need to be keep in a safe place. The advantage of using such a system is the private key is not required by the other party to perform encryption. Since the private key does not need to be transferred to the second party there is no risk of the private key being intercepted by a 3rd party. Public Key encryption is slower when compared with symmetric key so it is not always suitable for every application. The math used is complex but to put it simply it uses the modulus or remainder operator. For example, if you wanted to solve X mod 5 = 2, the possible solutions would be 2, 7, 12 and so on. The private key provides additional information which allows the problem to be solved easily. The math is more complex and uses much larger numbers than this but basically public and private key encryption rely on the modulus operator to work.
Combing The Two
There are two reasons you want to combine the two. The first is that often communication will be broken into two steps. Key exchange and data exchange. For key exchange, to protect the key used in data exchange it is often encrypted using public key encryption. Although slower than symmetric key encryption, this method ensures the key cannot accessed by a 3rd party while being transferred. Since the key has been transferred using a secure channel, a symmetric key can be used for data exchange. In some cases, data exchange may be done using public key encryption. If this is the case, often the data exchange will be done using a small key size to reduce the processing time.
The second reason that both may be used is when a symmetric key is used and the key needs to be provided to multiple users. For example, if you are using encryption file system (EFS) this allows multiple users to access the same file, which includes recovery users. In order to make this possible, multiple copies of the same key are stored in the file and protected from being read by encrypting it with the public key of each user that requires access.
References
"Public-key cryptography" http://en.wikipedia.org/wiki/Public-k...
"Encryption" http://en.wikipedia.org/wiki/Encryption

Views: 470655
itfreetraining

RSA Public Key Encryption Algorithm (cryptography). How & why it works. Introduces Euler's Theorem, Euler's Phi function, prime factorization, modular exponentiation & time complexity.
Link to factoring graph: http://www.khanacademy.org/labs/explorations/time-complexity

Views: 557185
Art of the Problem

MIT 6.042J Mathematics for Computer Science, Spring 2015
View the complete course: http://ocw.mit.edu/6-042JS15
Instructor: Albert R. Meyer
License: Creative Commons BY-NC-SA
More information at http://ocw.mit.edu/terms
More courses at http://ocw.mit.edu

Views: 17916
MIT OpenCourseWare

Nicolas Sendrier of the French Institute for Research in Computer Science and Automation presented an invited talk on code-based public-key cryptography at the 2014 PQCrypto summer school in October, 2014.
PQCrypto Summer School: https://pqcrypto2014.uwaterloo.ca/summer-school/
Find out more about IQC!
Website - https://uwaterloo.ca/institute-for-qu...
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Views: 1072
Institute for Quantum Computing

The history behind public key cryptography & the Diffie-Hellman key exchange algorithm.
We also have a video on RSA here: https://www.youtube.com/watch?v=wXB-V_Keiu8

Views: 620863
Art of the Problem

Daniele Micciancio of the University of California, San Diego presented an invited talk on lattice-based public key cryptography at the 2014 PQCrypto summer school in October, 2014.
PQCrypto Summer School: https://pqcrypto2014.uwaterloo.ca/summer-school/
Find out more about IQC!
Website - https://uwaterloo.ca/institute-for-qu...
Facebook - https://www.facebook.com/QuantumIQC
Twitter - https://twitter.com/QuantumIQC

Views: 2037
Institute for Quantum Computing

Clip 5/5
Speaker: Jintai Ding · University of Cincinnati
Public key cryptography is an indispensable part of most modern communication systems. However, quantum computers can break cryptosystems like RSA, which are based on
For more information go to the Cerias website (http://bit.ly/dsFCBF)

Views: 70
Christiaan008

Recorded: 02/23/2005
CERIAS Security Seminar at Purdue University
Perturbation of Multivariable Public-key Cryptosystems
Jintai Ding, University of Cincinnati
Public key cryptography is an indispensable part of most modern communication
systems. However, quantum computers can break cryptosystems
like RSA, which are based on
Jintai Ding is currently an associate professor in Department of
Mathematical Sciences at the University of Cincinnati. He received his Ph.D.
in Mathematics from Yale in 1995. He received the Zhong Jia Qing prize from
the Chinese Mathematical Society in 1990 and the Sloan Dissertation
Fellowship in 1994-1995. Before he moved to Cincinnati in 1998, he worked
as a lecturer at the Research Institute of Mathematical Sciences of Kyoto
University in Japan for three years. His early works are in quantum groups
and in the last few years, his main interest is in the area of the
multivariable public key cryptosystems. (Visit: www.cerias.purude.edu)

Views: 162
ceriaspurdue

https://8gwifi.org/CipherFunctions.jsp
Reference book: http://leanpub.com/crypto
Cryptographic Algorithms generally fall into one of two different categories, or are a combination of both.
Symmetric
Fast
Only provide confidentiality
Examples: DES, AES, Blowfish, RC4, RC5
Asymmetric
Large mathematical operations make it slower than symmetric algorithms
No need for out of band key distribution (public keys are public!)
Scales better since only a single key pair needed per individual
Can provide authentication and nonrepudiation
Examples: RSA, El Gamal, ECC, Diffie-Hellman
problem with symmetric key cryptography
DES (Data Encryption Standard)
64 bit key that is effectively 56 bits in strength
Actual algorithm is called DEA (Data Encryption Algorithm)
DES Modes
Electronic Code Book
Cipher Block Chaining (most commonly used for general purpose encryption)
Cipher Feedback
Output Feedback
Counter Mode (used in IPSec)
3DES
112-bit effective key length
Uses either 2 or 3 different smaller keys in one of several modes
Modes
EEE2/3
EDE2/3
AES
NIST replaced DES in 1997 with this
Uses the Rijndael algorithm
Supports key/block sizes of 128, 192, and 256 bits
Uses 10/12/14 rounds as block size increases
IDEA (International Data Encryption Algorithm)
Operates on 64 bit blocks in 8 rounds with 128 bit key
Considered stronger than DES and is used in PGP
Blowfish
64 bit block cipher with up to 448 bit key and 16 rounds
Designed by Bruce Schneier
RC4
Stream cipher with variable key size created by Ron Rivest
RC5
Another Rivest cipher
Block cipher with 32/64/128 bit blocks and keys up to 2048 bits
RC6
Beefier version of RC5 submitted as AES candidate
CAST
64 bit block cipher with keys between 40-128 bits with 12-16 rounds depending on key length
CAST-256 used 128-bit blocks and keys from 128-256 bits using 48 rounds
SAFER (Secure and Fast Encryption Routine)
Set of patent-free algorithms in 64 and 128 bit block variants
Variation used in Bluetooth
Twofish
Adapted version of Blowfish with 128 bit blocks, 128-256 bit keys and 16 rounds
AES Finalist
Kryptografie mit symmetrischem Schlüssel
symmetric key cryptography
symmetric key cryptography tutorial
symmetric key cryptography example
symmetric key cryptography vs asymmetric key cryptography
symmetric and asymmetric key cryptography
symmetric key cryptography
Kryptografie mit symmetrischem Schlüssel
Kryptographie mit symmetrischem Schlüssel
Kryptographie mit symmetrischem Schlüssel
Kryptografie mit symmetrischem Schlüssel und asymmetrische Schlüsselkryptographie
symmetrische und asymmetrische Schlüsselkryptographie
Kryptografie mit symmetrischem Schlüssel

Views: 40681
Zariga Tongy

How do you secure messages over the internet? How do quantum computers break it? How do you fix it? Why don't you watch the video to find out? Why does this description have so many questions? Why are you still reading? What is the meaning of life?
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CLARIFICATIONS:
You don't actually need a quantum computer to do quantum-safe encryption. As briefly mentioned at 7:04 , there are encryption schemes that can be run on regular computers that can't be broken by quantum computers.
CORRECTIONS:
[2:18] Technically, you can use any key to encrypt or decrypt whatever you want. But there's a specific way to use them that's useful, which is what's shown in the video.
[5:36] In RSA, depending on exactly what you mean by "private key", neither key is actually derivable from the other. When they are created, they are generated together from a common base (not just the public key from the private key). But typically, the file that stores the "private key" actually contains a bit more information than just the private key. For example, in PKCS #1 RSA private key format ( https://tools.ietf.org/html/rfc3447#appendix-A.1.2 ), the file technically contains the entire public key too. So in short, you technically can't get the public key from the private key or vice versa, but the file that contains the private key can hold more than just the private key alone, making it possible to retrieve the public key from it.
Video links:
Encryption and HUGE numbers - Numberphile
https://youtu.be/M7kEpw1tn50
The No Cloning Theorem - minutephysics
https://youtu.be/owPC60Ue0BE
Quantum Entanglement & Spooky Action at a Distance - Veritasium
https://youtu.be/ZuvK-od647c
Sources:
Quantum Computing for Computer Scientists
http://books.google.ca/books/about/Quantum_Computing_for_Computer_Scientist.html?id=eTT0FsHA5DAC
Random person talking about Quantum MITM attacks
http://crypto.stackexchange.com/questions/2719/is-quantum-key-distribution-safe-against-mitm-attacks-too
The Ekert Protocol (i.e. E91)
http://www.ux1.eiu.edu/~nilic/Nina's-article.pdf
Annealing vs. Universal Quantum Computers
https://medium.com/quantum-bits/what-s-the-difference-between-quantum-annealing-and-universal-gate-quantum-computers-c5e5099175a1
Images, Documents, and Screenshots:
Post-Quantum Cryptography initiatives
http://csrc.nist.gov/groups/ST/post-quantum-crypto/cfp-announce-dec2016.html
http://pqcrypto.eu.org/docs/initial-recommendations.pdf
Internet map (Carna Botnet)
http://census2012.sourceforge.net/
Quantum network maps
https://www.slideshare.net/ADVAOpticalNetworking/how-to-quantumsecure-optical-networks
http://www.secoqc.net/html/press/pressmedia.html
IBM Quantum
http://research.ibm.com/ibm-q/
Music:
YouTube audio library:
Blue Skies
Incompetech:
Jay Jay
Pamgaea
The House of Leaves
Premium Beat:
Cutting Edge Technology
Second Time Around
Swoosh 1 sound effect came from here:
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...and is under this license:
https://creativecommons.org/licenses/sampling+/1.0/

Views: 615194
Frame of Essence

Clip 1/5
Speaker: Jintai Ding · University of Cincinnati
Public key cryptography is an indispensable part of most modern communication systems. However, quantum computers can break cryptosystems like RSA, which are based on
For more information go to the Cerias website (http://bit.ly/dsFCBF)

Views: 119
Christiaan008

Title: Cryptanalysis of the McEliece Public Key Cryptosystem Based on Polar Codes
Authors: Magali Bardet, Julia Chaulet, Vlad Dragoi, Ayoub Otmani, and Jean-Pierre Tillich
7th International Conference on Post-Quantum Cryptography PQCrypto 2016
https://pqcrypto2016.jp/program/
Proceedings
http://www.springer.com/jp/book/9783319293592

Views: 361
PQCrypto 2016

Thanks to all of you who support me on Patreon. You da real mvps! $1 per month helps!! :) https://www.patreon.com/patrickjmt !! Part 1: https://youtu.be/PkpFBK3wGJc
Please consider being a supporter on Patreon! https://www.patreon.com/patrickjmt
Twitter: @Patrick_JMT
In this video I show mathematically for RSA encryption works by going through an example of sending an encrypted message!
If you are interested in seeing how Euclid's algorithm would work, check out this video by Emily Jane: https://www.youtube.com/watch?v=fz1vxq5ts5I
A big thanks to the 'Making & Science team at Google' for sponsoring this video!
Please like and share using hashtag #sciencegoals

Views: 40056
patrickJMT

[Recorded Jan 26, 2005]
Whitfield Diffie, a key figure in the discovery of public-key cryptography, traces the growth of information security through the 20th century and into the 21st. In the 1970s, the world of information security was transformed by public-key cryptography, the radical revision of cryptographic thinking that allowed people with no prior contact to communicate securely. "Public key" solved security problems born of the revolution in information technology that characterized the 20th century and made Internet commerce possible. Security problems rarely stay solved, however. Continuing growth in computing, networking, and wireless applications have given rise to new security problems that are already confronting us.

Views: 105153
Computer History Museum

What is POST-QUANTUM CRYPTOGRAPHY? What does POST-QUANTUM CRYPTOGRAPHY mean? POST-QUANTUM CRYPTOGRAPHY meaning - POST-QUANTUM CRYPTOGRAPHY definition - POST-QUANTUM CRYPTOGRAPHY explanation.
Source: Wikipedia.org article, adapted under https://creativecommons.org/licenses/by-sa/3.0/ license.
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Post-quantum cryptography refers to cryptographic algorithms (usually public-key algorithms) that are thought to be secure against an attack by a quantum computer. This is not true for the most popular public-key algorithms, which can be efficiently broken by a sufficiently large quantum computer. The problem with the currently popular algorithms is that their security relies on one of three hard mathematical problems: the integer factorization problem, the discrete logarithm problem or the elliptic-curve discrete logarithm problem. All of these problems can be easily solved on a sufficiently powerful quantum computer running Shor's algorithm. Even though current, publicly known, experimental quantum computers are too small to attack any real cryptographic algorithm, many cryptographers are designing new algorithms to prepare for a time when quantum computing becomes a threat. This work has gained greater attention from academics and industry through the PQCrypto conference series since 2006 and more recently by several workshops on Quantum Safe Cryptography hosted by the European Telecommunications Standards Institute (ETSI) and the Institute for Quantum Computing.
In contrast to the threat quantum computing poses to current public-key algorithms, most current symmetric cryptographic algorithms and hash functions are considered to be relatively secure against attacks by quantum computers. While the quantum Grover's algorithm does speed up attacks against symmetric ciphers, doubling the key size can effectively block these attacks. Thus post-quantum symmetric cryptography does not need to differ significantly from current symmetric cryptography.

Views: 202
The Audiopedia

A Google TechTalk, 2018-12-05, presented by Alessandro Barenghi
ABSTRACT: This talk will present LEDAkem and LEDApkc, a key agreement scheme and a public key encryption scheme resistant against attacks with both classical and quantum computers.
In this talk I will present the schemes and report recent results on
how we can automatically generate key sizes and cryptosystem parameters tailored for a desired security level, providing practical performance figures.
About the speaker: Alessandro Barenghi is currently assistant professor at Politecnico di Milano, and one of the proposers of the LEDAkem/LEDApkc cryptoschemes to the NIST post-quantum standardization initiative.

Views: 1023
GoogleTechTalks

Clip 4/5
Speaker: Jintai Ding · University of Cincinnati
Public key cryptography is an indispensable part of most modern communication systems. However, quantum computers can break cryptosystems like RSA, which are based on
For more information go to the Cerias website (http://bit.ly/dsFCBF)

Views: 62
Christiaan008

Clip 2/5
Speaker: Jintai Ding · University of Cincinnati
Public key cryptography is an indispensable part of most modern communication systems. However, quantum computers can break cryptosystems like RSA, which are based on
For more information go to the Cerias website (http://bit.ly/dsFCBF)

Views: 30
Christiaan008

Fundamental concepts of Diffie-Hellman Key exchange are discussed. ElGamal Cryptosystem is presented. Elliptic curves are Analyzed.

Views: 443
Scholartica Channel

Spies used to meet in the park to exchange code words, now things have moved on - Robert Miles explains the principle of Public/Private Key Cryptography
note1: Yes, it should have been 'Obi Wan' not 'Obi One' :)
note2: The string of 'garbage' text in the two examples should have been different to illustrate more clearly that there are two different systems in use.
http://www.facebook.com/computerphile
https://twitter.com/computer_phile
This video was filmed and edited by Sean Riley.
Computer Science at the University of Nottingham: http://bit.ly/nottscomputer
Computerphile is a sister project to Brady Haran's Numberphile. See the full list of Brady's video projects at: http://bit.ly/bradychannels

Views: 421945
Computerphile

http://spirent.com Presentation on how to use Quantum Key Distribution (QKD) to set up a secrete key between two parties. Also a quick overview of the protocol BB84. Sometimes known as Quantum cryptography.

Views: 7598
alantalkstech

Namaskaar Dosto, is video mein maine aapko encryption ke baare mein bataya hai, aap sabhi ne computer aur internet use karte time Encryption aur decryption ke baare mein jarur suna hoga, usme aapko SSL encrytpion TSL Encryption, Public Key encryption, private key encryption wagereh ke baare mein bhi suna hoga, aur abhi recently whatsapp ne bhi end to end encryption launch kiya hai, toh aise mein hamare man mein bahut se sawaal hai ki aakhir yeh encryption hota kya hai? Encryption hum hamari email pe bhi use karte hai, aur hum online banking karte time bhi encryption ka use karte hai. Mujhe umeed hai ki yeh video dekhne ke baad aap encryption aur decryption ke baare mein sab kuch jaan jayenge, aur saath hi saath public key encryption ke baare mein bhi samajh jayenge. aur aap aaraam se whatsapp ke encryption feature ko bhi use kar payenge.
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Views: 185248
Technical Guruji

This episode is brought to you by Squarespace: http://www.squarespace.com/physicsgirl
With recent high-profile security decryption cases, encryption is more important than ever. Much of your browser usage and your smartphone data is encrypted. But what does that process actually entail? And when computers get smarter and faster due to advances in quantum physics, how will encryption keep up?
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Writer: Sophia Chen
Animator: Kyle Norby
Special thanks to Nathan Lysne
Source:
http://gva.noekeon.org/QCandSKD/QCand...
http://physicsworld.com/cws/article/n...
https://epic.org/crypto/export_contro...
http://fas.org/irp/offdocs/eo_crypt_9...
Music: APM and YouTube

Views: 269984
Physics Girl

What is KNAPSACK CRYPTOSYSTEM? What does KNAPSACK CRYPTOSYSTEM mean? KNAPSACK CRYPTOSYSTEM meaning - KNAPSACK CRYPTOSYSTEM definition - KNAPSACK CRYPTOSYSTEM explanation.
Source: Wikipedia.org article, adapted under https://creativecommons.org/licenses/by-sa/3.0/ license.
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Knapsack Cryptosystems are cryptosystems which security is based on the hardness of solving the knapsack problem. While such systems have been existing for quite a long time, they remain quite unpopular because a lot of such systems have been broken. However that type of cryptosystem is a good candidate for post-quantum cryptography
The most famous knapsack cryptosystem is the Merkle-Hellman Public Key Cryptosystem, one of the first public key cryptosystem, published the same year as the RSA cryptosystem. However this system has been broken by several attacks : one from Shamir, one by Adleman, and the low density attack.
However, there exist modern knapsack cryptosystems that are considered secure so far: among them is Nasako-Murakami 2006.
What is interesting with those systems is that the Knapsack problem, in the settings where no attack were found, is believed to be difficult to solve even by a quantum computer. This is not the case for systems as RSA relying on the problem of factoring big integers, a problem that is solved in linear time by Shor's quantum algorithm.

Views: 603
The Audiopedia

Jintai Ding of the University of Cincinnati and the Chinese Academy of Sciences presented a talk titled: ZHFE, a new multivariate public key encryption scheme at the 2014 PQCrypto conference in October, 2014.
Abstract: In this paper we propose a new multivariate public key encryption scheme named ZHFE. The public key is constructed using as core map two high rank HFE polynomials. The inversion of the public key is performed using a low degree polynomial of Hamming weight three. This low degree polynomial is obtained from the two high rank HFE polynomials, by means of a special reduction method that uses HFE polynomials. We show that ZHFE is relatively efficient and the it is secure against the main attacks that have threatened the security of HFE. We also propose parameters for a practical implementation of ZHFE.
PQCrypto
2014 Book: http://www.springer.com/computer/security+and+cryptology/book/978-3-319-11658-7
Workshop: https://pqcrypto2014.uwaterloo.ca/
Find out more about IQC!
Website - https://uwaterloo.ca/institute-for-qu...
Facebook - https://www.facebook.com/QuantumIQC
Twitter - https://twitter.com/QuantumIQC

Views: 1410
Institute for Quantum Computing

Clip 3/5
Speaker: Jintai Ding · University of Cincinnati
Public key cryptography is an indispensable part of most modern communication systems. However, quantum computers can break cryptosystems like RSA, which are based on
For more information go to the Cerias website (http://bit.ly/dsFCBF)

Views: 33
Christiaan008

Security+ Training Course Index: http://professormesser.link/sy0401
Professor Messer’s Course Notes: http://professormesser.link/sy0401cn
Frequently Asked Questions: http://professormesser.link/faq
- - - - -
The creation and use of cryptography has also included new ways to keep our data private. In this video, you’ll learn about the use of elliptic curves to create encryption keys and how quantum cryptography can be used for spy-proof secure channels.
- - - - -
Download entire video course: http://professormesser.link/401adyt
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Views: 22757
Professor Messer

This animation by the Centre for Quantum Technologies at the National University of Singapore illustrates the process of quantum key distribution using entangled photons. The goal is for two people in different places to end up with identical keys by measuring these photons. We want these people - usually given the names Alice and Bob - to have a random sequence of 1s and 0s that they can use to scramble (and then unscramble) a message. The presence of entanglement between the photons means that any snooping will be revealed. Note: this animation has no sound.
See also our video series on cryptography: https://www.youtube.com/playlist?list=PL4CHL5j4XhurVKJz16Qg6qj0toMHyLh7q

Views: 25546
Centre for Quantum Technologies

What is QUANTUM KEY DISTRIBUTION? What does QUANTUM KEY DISTRIBUTION mean? QUANTUM KEY DISTRIBUTION meaning - QUANTUM KEY DISTRIBUTION definition - QUANTUM KEY DISTRIBUTION explanation.
Source: Wikipedia.org article, adapted under https://creativecommons.org/licenses/by-sa/3.0/ license.
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Quantum key distribution (QKD) uses quantum mechanics to guarantee secure communication. It enables two parties to produce a shared random secret key known only to them, which can then be used to encrypt and decrypt messages. It is often incorrectly called quantum cryptography, as it is the best-known example of a quantum cryptographic task.
An important and unique property of quantum key distribution is the ability of the two communicating users to detect the presence of any third party trying to gain knowledge of the key. This results from a fundamental aspect of quantum mechanics: the process of measuring a quantum system in general disturbs the system. A third party trying to eavesdrop on the key must in some way measure it, thus introducing detectable anomalies. By using quantum superpositions or quantum entanglement and transmitting information in quantum states, a communication system can be implemented that detects eavesdropping. If the level of eavesdropping is below a certain threshold, a key can be produced that is guaranteed to be secure (i.e. the eavesdropper has no information about it), otherwise no secure key is possible and communication is aborted.
The security of encryption that uses quantum key distribution relies on the foundations of quantum mechanics, in contrast to traditional public key cryptography, which relies on the computational difficulty of certain mathematical functions, and cannot provide any mathematical proof as to the actual complexity of reversing the one-way functions used. QKD has provable security based on information theory, and forward secrecy.
Quantum key distribution is only used to produce and distribute a key, not to transmit any message data. This key can then be used with any chosen encryption algorithm to encrypt (and decrypt) a message, which can then be transmitted over a standard communication channel. The algorithm most commonly associated with QKD is the one-time pad, as it is provably secure when used with a secret, random key. In real-world situations, it is often also used with encryption using symmetric key algorithms like the Advanced Encryption Standard algorithm.

Views: 194
The Audiopedia

The Future of Cybersecurity: Zeroing In On Un-Hackable Data With Quantum Key Distribution
Speaker: Alexander Ling, Centre for Quantum Technologies, National University of Singapore
* Filmed at EmTech Asia on 14 February 2017 *
Improvements in quantum computing potentially place existing public-key cryptosystems under threat. On the other hand, the ability to generate and distribute quantum signals in the form of individual light particles has matured over the last decade. This has been utilized for the automatic distribution of encryption keys, and is known as Quantum Key Distribution (QKD). Alex will discuss the benefits and challenges when implementing QKD over short and long distances.

Views: 568
Centre for Quantum Technologies

This is a basic introduction into quantum key distribution technology, accessible to undergraduate students and above. The lecture explains society's need for this technology, how quantum cryptography works, shows today's commercial and research hardware, and touches on the question of hacking attacks against it.
Download presentation slides:
PowerPoint (63 MiB, with videos and animations) http://www.vad1.com/lab/presentations/Makarov-20140930-UWaterloo-phys10-undergrad-seminar.pptx
PDF (6.8 MiB, static images only) http://www.vad1.com/lab/presentations/Makarov-20140930-UWaterloo-phys10-undergrad-seminar.pdf
This lecture was given at University of Waterloo undergraduate physics seminar (Phys10) on September 30th, 2014.
If you are more interested in quantum cryptography technology and have more time, consider watching a longer lecture series by Vadim Makarov: https://www.youtube.com/watch?v=ToOLbdrWst4
Find out more about IQC!
Website - https://uwaterloo.ca/institute-for-quantum-computing/
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Views: 6969
Institute for Quantum Computing

Cracking RSA-2048 Cryptography using Shor's Algorithm on a Quantum Computer
We demonstrate live a Pure/Undiluted Implementation of Shor's Algorithm on a 100,000+ Qubit Quantum Computer Simulator by Automatski.
We have hence cracked RSA-2048 and all Existing Cryptography in The World

Views: 293
Automatski Solutions

Learn more advanced front-end and full-stack development at: https://www.fullstackacademy.com
Public Key Encryption is a cryptographic system that uses pairs of keys: public keys which may be known widely, and private keys known only to the message's recipient. In a public key encryption system, the public key is used to encrypt messages and only the corresponding private key can be used to decrypt them. In this video, we discuss the advantages of this system by giving public key encryption examples.
Watch this video to learn:
- The basics of cryptography
- Common problems in symmetric key encryption
- How public key encryption solves some of those problems

Views: 339
Fullstack Academy

Taylor Daniels of the University of Louisville presented a talk titled: Differential properties of the H F E cryptosystem at the 2014 PQCrypto conference in October, 2014.
Abstract: Multivariate Public Key Cryptography (MPKC) has been put forth as a possible post-quantum family of cryptographic schemes. These schemes lack provable security in the reduction theoretic sense, and so their security against yet undiscovered attacks remains uncertain. The effectiveness of differential attacks on various field-based systems has prompted the investigation of differential properties of multivariate schemes to determine the extent to which they are secure from differential adversaries. Due to its role as a basis for both encryption and signature schemes we contribute to this investigation focusing on the H F E cryptosystem. We derive the differential symmetric and invariant structure of the H F E central map and that of H F E- and provide a collection of parameter sets which make these H F E systems provably secure against a differential symmetric or differential invariant attack.
PQCrypto
2014 Book: http://www.springer.com/computer/security+and+cryptology/book/978-3-319-11658-7
Workshop: https://pqcrypto2014.uwaterloo.ca/
Find out more about IQC!
Website - https://uwaterloo.ca/institute-for-qu...
Facebook - https://www.facebook.com/QuantumIQC
Twitter - https://twitter.com/QuantumIQC

Views: 451
Institute for Quantum Computing

https://asecuritysite.com/encryption/lwe2

Views: 270
Bill Buchanan OBE

Today we’re going to talk about how to keep information secret, and this isn’t a new goal. From as early as Julius Caesar’s Caesar cipher to Mary, Queen of Scots, encrypted messages to kill Queen Elizabeth in 1587, theres has long been a need to encrypt and decrypt private correspondence. This proved especially critical during World War II as Allan Turing and his team at Bletchley Park attempted to decrypt messages from Nazi Enigma machines, and this need has only grown as more and more information sensitive tasks are completed on our computers. So today, we’re going to walk you through some common encryption techniques such as the Advanced Encryption Standard (AES), Diffie-Hellman Key Exchange, and RSA which are employed to keep your information safe, private, and secure.
Note: In October of 2017, researchers released a viable hack against WPA2, known as KRACK Attack, which uses AES to ensure secure communication between computers and network routers. The problem isn't with AES, which is provably secure, but with the communication protocol between router and computer. In order to set up secure communication, the computer and router have to agree through what's called a "handshake". If this handshake is interrupted in just the right way, an attacker can cause the handshake to fault to an insecure state and reveal critical information which makes the connection insecure. As is often the case with these situations, the problem is with an implementation, not the secure algorithm itself. Our friends over at Computerphile have a great video on the topic: https://www.youtube.com/watch?v=mYtvjijATa4
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Views: 205647
CrashCourse

In this video you will learn how to solve knapsack problem in cryptography .. encrytion and decryption of any letter using ASCII value and convert them into binary .. which will make hard of any intruder to decrypt the message
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In this lecture we have taught about Knapsack Public Key Cryptography and how to solve it with example.
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Views: 9904
Quick Trixx

How keys are distributed is vital to any encryption system. Find out how to do it with the Diffie–Hellman key exchange and using public-key cryptography. Find out more: https://goo.gl/qI6jxZ
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Views: 42068
Android Authority

A short video attempting to explain the Bennett & Brassard quantum cryptography protocol.
I've omitted any mention of the particular details of quantum physics that would be involved in actual real-world implementations, such as particle polarization axes, spin, and so forth, instead replacing them with abstract "processes" and freakish mysterious "machines". The physical details (interesting though they are) are not needed to understand the basics of the protocol, and I'm no physicist, so I'd probably mess them up if I tried (assuming I haven't already!).
Making these images has increased my affection for Microsoft PowerPoint, and putting them all into a video has hugely exacerbated my hatred for Windows Movie Maker.
NOTE:
An important missing piece of information: When Alice sends qubits to Bob, she chooses between process A and process B randomly for each qubit.
NOTE 2:
The following video explains BB84 as well, and gives more detail regarding the physics details:
http://www.youtube.com/watch?v=7SMcf1MdOaQ
NOTE 3:
Here is another very interesting video about quantum cryptography. Any given real-world implementation, despite using the BB84 protocol, is bound to expose weaknesses that can be exploited. For example:
http://www.youtube.com/watch?v=T0WnUlF2eAo

Views: 44691
Creature Mann

I will report on recent results about quantum algorithms for solving computational problems in number theory. I will show how they impact the security of certain post-quantum cryptosystems. Shor's quantum algorithm for factoring large integers and solving the discrete logarithm problem has been the motivation for an entire new area of research in cryptology: namely "post-quantum" cryptography. It consists of designing new cryptographic primitives which will resist attacks from quantum computers. In a recent work in collaboration with Fang Song, I presented a quantum polynomial time algorithm for solving the so-called "Principal Ideal Problem" (among other things) in arbitrary fields. We will see how this impacts the security of some ring-based proposals for quantum resistant cryptography. In collaboration with David Jao and Anirudh Sankar, I also described a quantum algorithm which finds an isogeny between two given supersingular curves over a finite field, a hard problem on which some post-quantum cryptosystem rely. Finally, if there is enough time, I'll mention some recent work on factorization.
See more on this video at https://www.microsoft.com/en-us/research/video/quantum-algorithms-number-theory-relevance-cryptography/

Views: 1529
Microsoft Research

Of all the interfaces between physics and computer science that have grown up in the last few decades, quantum computing is one of the most exciting. Much of this excitement was driven by Peter Shor’s 1994 discovery that quantum computers can efficiently factor large integers, and thus break the RSA public-key cryptosystem. After describing how Shor’s algorithm works, I will describe why many of us were hopeful that a similar algorithm could work for Graph Isomorphism, another problem not known to be efficiently solvable by classical computers.
Cristopher Moore received his Ph.D. in Physics from Cornell. Since 2012, Moore has been a resident professor at the Santa Fe Institute ; he has also held visiting positions at École Polytechnique, École Normale Superieure du Lyon, the University of Michigan, and Northeastern University. He is working at the boundaries between physics and computer science, ranging from quantum computing, to phase transitions in NP-complete problems.

Views: 52
Département de Physique de l'ENS

This video shows an entertaining way to introduce Computer Science to school students.
For the next part, see http://nz.youtube.com/watch?v=iDVH3oCTc2c
For the first part in the series, see http://nz.youtube.com/watch?v=voqghyZbZxo
The full show is available in one clip at http://nz.youtube.com/watch?v=VpDDPWVn5-Q
For more information, see http://csunplugged.org

Views: 32977
UC Computer Science Education

Post-Quantum Key Exchange for the TLS Protocol from the Ring Learning with Errors Problem
Douglas Stebila
Presented at the
2015 IEEE Symposium on Security & Privacy
May 18--20, 2015
San Jose, CA
http://www.ieee-security.org/TC/SP2015/
ABSTRACT
Lattice-based cryptographic primitives are believed to offer resilience against attacks by quantum computers. We demonstrate the practicality of post-quantum key exchange by constructing cipher suites for the Transport Layer Security (TLS) protocol that provide key exchange based on the ring learning with errors (R-LWE) problem, we accompany these cipher suites with a rigorous proof of security. Our approach ties lattice-based key exchange together with traditional authentication using RSA or elliptic curve digital signatures: the post-quantum key exchange provides forward secrecy against future quantum attackers, while authentication can be provided using RSA keys that are issued by today's commercial certificate authorities, smoothing the path to adoption. Our cryptographically secure implementation, aimed at the 128-bit security level, reveals that the performance price when switching from non-quantum-safe key exchange is not too high. With our R-LWE cipher suites integrated into the Open SSL library and using the Apache web server on a 2-core desktop computer, we could serve 506 RLWE-ECDSA-AES128-GCM-SHA256 HTTPS connections per second for a 10 KiB payload. Compared to elliptic curve Diffie-Hellman, this means an 8 KiB increased handshake size and a reduction in throughput of only 21%. This demonstrates that provably secure post-quantum key-exchange can already be considered practical.

Views: 1225
IEEE Symposium on Security and Privacy

Clip 5/6
Speakers: Qin Liu ,Sebastien Sauge
This presentation will show the first experimental implementation of an eavesdropper for quantum cryptosystem. Although quantum cryptography has been proven unconditionally secure, by exploiting physical imperfections (detector vulnerability) we have successfully built an intercept-resend attack and demonstrated eavesdropping under realistic conditions on an installed quantum key distribution line. The actual eavesdropping hardware we have built will be shown during the conference.
For more information go to: http://events.ccc.de/congress/2009/Fahrplan/events/3576.en.html

Views: 175
Christiaan008

Title: Post-Quantum Cryptography: NIST's Plan for the Future
Speaker: Dustin Moody
7th International Conference on Post-Quantum Cryptography PQCrypto 2016
https://pqcrypto2016.jp/program/

Views: 1092
PQCrypto 2016

Most modern cryptography, and public-key crypto in particular, is based on mathematical problems that are conjectured to be infeasible (e.g., factoring large integers). Unfortunately, standard public-key techniques are often too inefficient to be employed in many environments; moreover, all commonly used schemes can in principle be broken by quantum computers. This talk will review my recent work on developing new mathematical foundations for cryptography, using geometric objects called lattices. Compared to more conventional proposals, lattice-based schemes offer a host of potential advantages: they are simple and highly parallelizable, they can be proved secure under mild worst-case hardness assumptions, and they remain unbroken by quantum algorithms. Due to the entirely different underlying mathematics, however, realizing even the most basic cryptographic notions has been a major challenge. Surprisingly, I will show that lattice-based schemes are also remarkably flexible and expressive, and that many important cryptographic goals can be achieved --- sometimes even more simply and efficiently than with conventional approaches. Some of our schemes provide interesting twists on old and cherished cryptographic notions, while others introduce entirely new concepts altogether.

Views: 2646
Microsoft Research

Clip 1/6
Speakers: Qin Liu ,Sebastien Sauge
This presentation will show the first experimental implementation of an eavesdropper for quantum cryptosystem. Although quantum cryptography has been proven unconditionally secure, by exploiting physical imperfections (detector vulnerability) we have successfully built an intercept-resend attack and demonstrated eavesdropping under realistic conditions on an installed quantum key distribution line. The actual eavesdropping hardware we have built will be shown during the conference.
For more information go to: http://events.ccc.de/congress/2009/Fahrplan/events/3576.en.html

Views: 744
Christiaan008