User Authentication - Authentication Tokens, Types pf Tokens – Challenge/Response and Time Based Tokens Keywords: Authentication Tokens in Security Token based Password Management Challenge/Response Based Token Time Based Token Network Security Notes
Views: 9093 Easy Engineering Classes
This video lecture is produced by S. Saurabh. He is B.Tech from IIT and MS from USA. In this lecture you will learn about 1. Authentication Protocol 2. Man in Middle attack 3. None 4. Replay Attack To study interview questions on Linked List watch http://www.youtube.com/playlist?list=PL3D11462114F778D7&feature=view_all To prepare for programming Interview Questions on Binary Trees http://www.youtube.com/playlist?list=PLC3855D81E15BC990&feature=view_all To study programming Interview questions on Stack, Queues, Arrays visit http://www.youtube.com/playlist?list=PL65BCEDD6788C3F27&feature=view_all To watch all Programming Interview Questions visit http://www.youtube.com/playlist?list=PLD629C50E1A85BF84&feature=view_all To learn about Pointers in C visit http://www.youtube.com/playlist?list=PLC68607ACFA43C084&feature=view_all To learn C programming from IITian S.Saurabh visit http://www.youtube.com/playlist?list=PL3C47C530C457BACD&feature=view_all
Views: 17754 saurabhschool
What is CHALLENGE-RESPONSE AUTHENTICATION? What does CHALLENGE-RESPONSE AUTHENTICATION mean? CHALLENGE-RESPONSE AUTHENTICATION meaning - CHALLENGE-RESPONSE AUTHENTICATION definition - CHALLENGE-RESPONSE AUTHENTICATION explanation. Source: Wikipedia.org article, adapted under https://creativecommons.org/licenses/by-sa/3.0/ license. SUBSCRIBE to our Google Earth flights channel - https://www.youtube.com/channel/UC6UuCPh7GrXznZi0Hz2YQnQ In computer security, challenge-response authentication is a family of protocols in which one party presents a question ("challenge") and another party must provide a valid answer ("response") to be authenticated. The simplest example of a challenge-response protocol is password authentication, where the challenge is asking for the password and the valid response is the correct password. Clearly an adversary who can eavesdrop on a password authentication can then authenticate itself in the same way. One solution is to issue multiple passwords, each of them marked with an identifier. The verifier can ask for any of the passwords, and the prover must have that correct password for that identifier. Assuming that the passwords are chosen independently, an adversary who intercepts one challenge-response message pair has no clues to help with a different challenge at a different time. For example, when other communications security methods are unavailable, the U.S. military uses the AKAC-1553 TRIAD numeral cipher to authenticate and encrypt some communications. TRIAD includes a list of three-letter challenge codes, which the verifier is supposed to choose randomly from, and random three-letter responses to them. For added security, each set of codes is only valid for a particular time period which is ordinarily 24 hours. A more interesting challenge-response technique works as follows: Say "Bob" is controlling access to some resource. Alice comes along seeking entry. Bob issues a challenge, perhaps "52w72y". Alice must respond with the one string of characters which "fits" the challenge Bob issued. The "fit" is determined by an algorithm "known" to Bob and Alice. (The correct response MIGHT be as simple as "63x83z" (each character of response one more than that of challenge)... but in the real world, the "rules" would be much more complex.) Bob issues a different challenge each time, and thus knowing a previous correct response... even if it isn't "hidden" by the means of communication used between Alice and Bob... is of no use. A part of Alice's response might convey that it is Alice (or the specific dongle she was supposed to be keeping secure) who is seeking authentication. Software in the 1980s and 1990s often used a similar method for copy protection: challenges would be questions like "What is the second word in the third paragraph on page 418 of the manual?". The security assumption was that copying the manual was more difficult than copying the software disk. Sometimes the manual would be printed in such a way that contemporary photocopy machines couldn't duplicate the pages. Challenge-response protocols are also used to assert things other than knowledge of a secret value. CAPTCHAs, for example, are a sort of variant on the Turing test, meant to determine whether a viewer of a Web application is a real person. The challenge sent to the viewer is a distorted image of some text, and the viewer responds by typing in that text. The distortion is designed to make automated optical character recognition (OCR) difficult and preventing a computer program from passing as a human. Non-cryptographic authentication were generally adequate in the days before the Internet, when the user could be sure that the system asking for the password was really the system they were trying to access, and that nobody was likely to be eavesdropping on the communication channel to observe the password being entered. To address the insecure channel problem, a more sophisticated approach is necessary. Many cryptographic solutions involve two-way authentication, where both the user and the system must each convince the other that they know the shared secret (the password), without this secret ever being transmitted in the clear over the communication channel, where eavesdroppers might be lurking. ....
Views: 2269 The Audiopedia
What is CRYPTOGRAPHIC NONCE? What does CRYPTOGRAPHIC NONCE mean? CRYPTOGRAPHIC NONCE meaning - CRYPTOGRAPHIC NONCE definition - CRYPTOGRAPHIC NONCE explanation. Source: Wikipedia.org article, adapted under https://creativecommons.org/licenses/by-sa/3.0/ license. SUBSCRIBE to our Google Earth flights channel - https://www.youtube.com/channel/UC6UuCPh7GrXznZi0Hz2YQnQ In cryptography, a nonce is an arbitrary number that may only be used once. It is similar in spirit to a nonce word, hence the name. It is often a random or pseudo-random number issued in an authentication protocol to ensure that old communications cannot be reused in replay attacks. They can also be useful as initialization vectors and in cryptographic hash function. A nonce is an arbitrary number used only once in a cryptographic communication, in the spirit of a nonce word. They are often random or pseudo-random numbers. Many nonces also include a timestamp to ensure exact timeliness, though this requires clock synchronization between organizations. The addition of a client nonce ("cnonce") helps to improve the security in some ways as implemented in digest access authentication. To ensure that a nonce is used only once, it should be time-variant (including a suitably fine-grained timestamp in its value), or generated with enough random bits to ensure a probabilistically insignificant chance of repeating a previously generated value. Some authors define pseudo-randomness (or unpredictability) as a requirement for a nonce. Authentication protocols may use nonces to ensure that old communications cannot be reused in replay attacks. For instance, nonces are used in HTTP digest access authentication to calculate an MD5 digest of the password. The nonces are different each time the 401 authentication challenge response code is presented, thus making replay attacks virtually impossible. The scenario of ordering products over the Internet can provide an example of the usefulness of nonces in replay attacks. An attacker could take the encrypted information and—without needing to decrypt—could continue to send a particular order to the supplier, thereby ordering products over and over again under the same name and purchase information. The nonce is used to give 'originality' to a given message so that if the company receives any other orders from the same person with the same nonce, it will discard those as invalid orders. A nonce may be used to ensure security for a stream cipher. Where the same key is used for more than one message and then a different nonce is used to ensure that the keystream is different for different messages encrypted with that key; often the message number is used. Secret nonce values are used by the Lamport signature scheme as a signer-side secret which can be selectively revealed for comparison to public hashes for signature creation and verification. Initialization vectors may be referred to as nonces, as they are typically random or pseudo-random. Nonces are used in proof-of-work systems to vary the input to a cryptographic hash function so as to obtain a hash for a certain input that fulfills certain arbitrary conditions. In doing so, it becomes far more difficult to create a "desirable" hash than to verify it, shifting the burden of work onto one side of a transaction or system. For example, proof of work, using hash functions, was considered as a means to combat email spam by forcing email senders to find a hash value for the email (which included a timestamp to prevent pre-computation of useful hashes for later use) that had an arbitrary number of leading zeroes, by hashing the same input with a large number of nonce values until a "desirable" hash was obtained. Similarly, the bitcoin block-chain hashing algorithm can be tuned to an arbitrary difficulty by changing the required minimum/maximum value of the hash so that the number of bitcoins awarded for new blocks does not increase linearly with increased network computation power as new users join. This is likewise achieved by forcing bitcoin miners to add nonce values to the value being hashed to change the hash algorithm output. Because cryptographic hash algorithms cannot easily be predicted based on their inputs, this makes the act of blockchain hashing and the possibility of being awarded bitcoins something of a lottery, where the first "miner" to find a nonce that delivers a desirable hash is awarded valuable bitcoins.
Views: 6898 The Audiopedia
In this playlist you will learn about the following topics Protocols, Layered Model Network components Uses of networks Traceroute and socket API Protocols and layering Reference models (Internet, OSI) History of the internet Physical and Direct Link Layer Simple link models (latency, bandwidth-delay product) Media and signals Modulation schemes (baseband, passband) Fundamental limits (Shannon) Framing Error detection schemes (checksum, CRC) Error correction schemes (Hamming) Retransmissions, Multiple access, Switching Retransmissions (ARQ) Multiplexing schemes (TDM. FDM) Random access / Ethernet (CSMA family) Wireless access / 802.11 Contention-free access / Token Ring LAN switching (switches vs. hubs, spanning tree, backward learning) Network Layer and Internetworking Datagram and virtual circuit models (IP, MPLS) IP addressing and forwarding (prefixes, longest matching prefix) IP helpers: ARP, DHCP Internetworking (fragmentation, path MTU discovery, ICMP) IPv4 and IPv6 Network Address Translation (NAT) Routing Shortest cost routing model Dijkstra's algorithm Flooding Distance Vector and Link-state Equal-cost multi-path routing Hierarchical routing (prefixes, aggregation, subnets) Multiple parties and policy (BGP) Transport Layer, Reliable Transport Sockets, ports and service APIs Reliable and unreliable delivery (TCP, UDP) Connection establishment and teardown Flow control and sliding windows Retransmission timeouts Congestion Control Fairness and Efficiency Additive Increase Multiplicative Decrease (AIMD) TCP congestion control (slow start, fast retransmission and recovery) Congestion avoidance (ECN) Web and Content Distribution Naming (DNS) Web protocols (HTTP, caching) Content Distribution Networks (CDNs) Peer-to-Peer (BitTorrent) Quality of Service and Real-Time Apps Streaming media and Conferencing Scheduling disciplines (FIFO, WFQ) Traffic shaping with Token Buckets Differentiated Services Rate and Delay Guarantees Optional: Network Security Encryption for Confidentiality and Authenticity Web security (SSL, DNSSEC) Wireless security (802.11i) Firewalls and Virtual Private Networks (VPNs) Distributed Denial of Service (DDOS) Computer Networks 1 OSI Model in Networking OSI model layers and their function (L1) 2 IP Address Basics: Classful Addressing dotted decimal notation 3 IP Address: Network ID and Host ID Network Mask 4 IP Address Subnet Supernet subnetmask 5 Classless IP Addressing: Subnet Mask, subnet block size, network address 6 Block Allocation of IP address Create subnets from block of IP address 7 Introduction to Interconnecting Devices: REPEATERS HUBS BRIDGE SWITCHES ROUTERS 8 VLAN: Virtual Lan concepts VLAN TRUNK and Switches 9 Address Resolution Protocol (ARP) and Reverse ARP explained Animated 10 Medium Access Control: Aloha and Slotted Aloha Protocol 11 Carrier Sense Multiple Access Protocol CSMA 12 CSMA/CD (Carrier Sense Multiple Access/ Collision Detection) 13 Network Address Translation (NAT) 14 Dynamic Host Configuration Protocol (DHCP) 15 Circuit Switching vs Packet Switching 16 Virtual Circuit Network Virtual Circuit switching 17 Domain Name Server (DNS) Name Server DNS how dns works 18 Internet Control Message Protocol (ICMP) ICMP protocol tutorial part 1 19 Internet Control Message Protocol (ICMP) : Error Message (Part 2) 20 Stop and Wait Protocol Stop and Wair ARQ Stop and Wait Flow control 21 GO BACK N ARQ Protocol Go back N sliding window 22 SELECTIVE REPEAT ARQ selective repeat sliding window protocol 23 Authentication Protocol Man In Middle Attack Replay Attack Nonce 24 Introduction to Public Key Cryptography Public Key Cryptography animation 25 Introduction to Digital Signature Public Key cryptography 26 RSA Algorithm and public key encryption rivest shamir adleman algorithm 27 Message Digest and Digital Signature Cryptographic Hash Function 28 Certification Authority (CA) Digital Certificate 29 Secure EMail How To Public Private Key Encryption Secure E-Mail PGP
Views: 199 Vijay S
https://8gwifi.org/hmacgen.jsp The Keyed-Hash Message Authentication Code HMAC tutorial FIPS PUB 198-1 The purpose of a MAC is to authenticate both the source of a message and its integrity without the use of any additional mechanisms. HMACs have two functionally distinct parameters, a message input and a secret key known only to the message originator and intended receiver(s). Additional applications of keyed-hash functions include their use in challenge-response identification protocols for computing responses, which are a function of both a secret key and a challenge message. Cryptographic key (key): a parameter used in conjunction with a cryptographic algorithm that determines the specific operation of that algorithm. In this Standard, the cryptographic key is used by the HMAC algorithm to produce a MAC on the data. Hash function: a mathematical function that maps a string of arbitrary length (up to a pre- determined maximum size) to a fixed length string. Keyed-hash message authentication code (HMAC): a message authentication code that uses a cryptographic key in conjunction with a hash function. Message Authentication Code (MAC): a cryptographic checksum that results from passing data through a message authentication algorithm. In this Standard, the message authentication algorithm is called HMAC, while the result of applying HMAC is called the MAC.
Views: 14759 Zariga Tongy
This video is part of an online course, Applied Cryptography. Check out the course here: https://www.udacity.com/course/cs387.
Views: 957 Udacity
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 CHAP and PAP authentication protocols have been a mainstay of network computing. In this video, you’ll learn how PAP and CHAP operates over the network and some of the advantages and disadvantages of using these protocols for authentication. - - - - - Download entire video course: http://professormesser.link/401adyt Get the course on MP3 audio: http://professormesser.link/401vdyt Subscribe to get the latest videos: http://professormesser.link/yt Calendar of live events: http://www.professormesser.com/calendar/ FOLLOW PROFESSOR MESSER: Professor Messer official website: http://www.professormesser.com/ Twitter: http://www.professormesser.com/twitter Facebook: http://www.professormesser.com/facebook Instagram: http://www.professormesser.com/instagram Google +: http://www.professormesser.com/googleplus
Views: 35585 Professor Messer
Security+ Training Course Index: http://professormesser.link/sy0501 Professor Messer’s Course Notes: http://professormesser.link/501cn Frequently Asked Questions: http://professormesser.link/faq - - - - - Some legacy authentication protocols are still in use today. In this video, you’ll learn about the operation of PAP, CHAP, and Microsoft’s MS-CHAP protocols. - - - - - Subscribe to get the latest videos: http://professormesser.link/yt Calendar of live events: http://www.professormesser.com/calendar/ FOLLOW PROFESSOR MESSER: Professor Messer official website: http://www.professormesser.com/ Twitter: http://www.professormesser.com/twitter Facebook: http://www.professormesser.com/facebook Instagram: http://www.professormesser.com/instagram Google +: http://www.professormesser.com/googleplus
Views: 27815 Professor Messer
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! 🐦 Follow me on Twitter: https://twitter.com/savjee ✏️ Check out my blog: https://www.savjee.be 👍🏻 Like my Facebook page: https://www.facebook.com/savjee
Views: 252368 Simply Explained - Savjee
DebConf13 Adding Challenge-Response Based Authentication Schemes To oath-toolkit and dynalogin Presenting the results / progress of a GSOC project Speakers: Fabian Grünbichler I am currently working on implementing OCRA (RFC 6287) in oath-toolkit and dynalogin as a Google Summer Of Code project. I would like to give a brief overview over the project, interaction with the community and my mentors, project outlook etc. http://penta.debconf.org/dc13_schedule/attachments/263_slide_oath_ocra_talk.pdf http://www.google-melange.com/gsoc/project/google/gsoc2013/fabiang/2001
Views: 236 Jalal Al-Haj
How symmetric key encryption can sometimes provide confidentiality as well as authentication; Limitations of authentication with encryption. Course material via: http://sandilands.info/sgordon/teaching
Views: 1513 Steven Gordon
Any help On this Assignment Ping Me, Just Ping Me @ MOM Assignments, WhatsApp: +91 8184943954 Email : [email protected] ================================================================== MCIS6173 Project 2 Encryption and Authentication An important part of any data communication is to secure the data to preserve its confidentiality. Also, to access a resource over a network, you have to possess the proper credentials that also need to be checked and securely exchanged. Keys are important part of any encryption algorithm used for protecting the data secrecy. Therefore, creating and exchanging these keys are very critical. In this assignment you will be asked to implement the MS-CHAP for authentication and the Diffie-Hellman algorithm for exchanging keys. Objectives: 1- Study how authentication can be done between supplicant/client and the verifier/server 2- Study how keying can happen without exchanging the keys 3- Using external resources to grasp info required for the project. 4- Being Able to implement one authentication algorithm 5- Being Able to implement an important keying algorithm 6- Writing client-server code and what is needed for these to communicate. 7- The introduction of using network address, socket, port number in working code. This assignment has two parts: 1- Authentication: a. You have to create a client – server application b. After starting/executing both , the following should happen c. The server side: i. Has a file of user accounts that you will be provided with; cred.txt ii. This file is used to check/extract the username and password of a user. iii. Does what the MS-CHAP verifier side does: 1. Create a challenge message 2. Sends the message to client 3. Receives the hashed response from the client 4. Adds the password of the client to the message 5. Hashes result and compare it to the received message 6. If there is a match, the server sends a message to the client: “Access Granted …. Welcome username” 7. If not, the server sends the message: ”Wrong password or username, please try again” 8. After the 3rd try, the server says: ”Try tomorrow” 9. Then the server goes off with a beep sound iv. The messages in 6, 7, 8 are displayed on the client screen d. The client side: i. The user Will be asked to enter a username and password ii. Does what the MS-CHAP supplicant side does: 1. Receives the message from server 2. Adds password to the message and hashes result 3. Sends the result to server. iii. The client will receive and display messages from the server about the success/failure of his/her login attempts 2- Keying: a. The client and server will exchange the p and g numbers. b. These 2 numbers have specific properties i. Check this link for more info about the algorithm: https://en.wikipedia.org/wiki/Diffie%E2%80%93Hellman_key_exchange ii. Also, check the material in the slides. iii. p is a prime number, and g is a primitive root modulo p. 1. I explained about that in the class and you can look for online resources for more information about these two numbers. iv. For simplicity, assume that the client chooses the p, and then the server has to find the g which follows the rule of iii. v. Then both client and the server should exchange and possess the p and g numbers. vi. When the keying is successful, both the server and client will display the shared key on their terminals. They must be the same, as you know. 3- Program start: a. When the client and server start, the user is given two choices: i. Authentication? Press: 1 ii. Keying? Press: 2 b. Depending on the choice, one of the scenarios above happens. Notes: 1- The project is to be done in groups of 3 or less. Groups have to be from the same section in case we have several sections. 3- Languages to be used are only python or java. 4- Name the solution file like: client.py and server.py OR client.java and server.java 5- Only the code files should be submitted per group. a. Do not submit other files like snapshots of the program 6- Your code should start with a block of comment. a. This comment block has: i. Students names and ids 7- You have to make sure that your code runs error-free, especially compilation errors. a. We will not debug or fix any errors. Very low score is expected in this case. 8- Be careful about the Path names/information. a. Always assume current folder/directory. 9- The command to run your code would be similar to: python2.6 client.py , and on another terminal screen: python2.6 server.py , OR java client , and on another terminal screen: java server 10- You will be given cred.txt file that has usernames and passwords that the server code has to access. 11- You can assume the IP address is the localhost, and port number is 10000 12- For simplicity, the message in MS-CHAP can be a numeric value, and the addition to the password can be a simple mathematical operation. Good Luck! https://youtu.be/DbNsBlBJYmE
Views: 26 MOM Assignments
What is DIGITAL SIGNATURE TRANSPONDER? What does DIGITAL SIGNATURE TRANSPONDER mean? DIGITAL SIGNATURE TRANSPONDER meaning - DIGITAL SIGNATURE TRANSPONDER definition - DIGITAL SIGNATURE TRANSPONDER explanation. Source: Wikipedia.org article, adapted under https://creativecommons.org/licenses/by-sa/3.0/ license. SUBSCRIBE to our Google Earth flights channel - https://www.youtube.com/channel/UC6UuCPh7GrXznZi0Hz2YQnQ The Texas Instruments digital signature transponder (DST) is a cryptographically enabled radio-frequency identification (RFID) device used in a variety of wireless authentication applications. The largest deployments of the DST include the Exxon-Mobil Speedpass payment system (approximately 7 million transponders), as well as a variety of vehicle immobilizer systems used in many late model Ford, Lincoln, Mercury, Toyota, and Nissan vehicles. The DST is an unpowered "passive" transponder which uses a proprietary block cipher to implement a challenge-response authentication protocol. Each DST tag contains a quantity of non-volatile RAM, which stores a 40-bit encryption key. This key is used to encipher a 40-bit challenge issued by the reader, producing a 40-bit ciphertext, which is then truncated to produce a 24-bit response transmitted back to the reader. Verifiers (who also possess the encryption key) verify this challenge by computing the expected result and comparing it to the tag response. Transponder encryption keys are user programmable, using a simple over-the-air protocol. Once correctly programmed, transponders may be "locked" through a separate command, which prevents further changes to the internal key value. Each transponder is factory provisioned with a 24-bit serial number and 8-bit manufacturer code. These values are fixed, and cannot be altered. Until 2005, the DST cipher (DST40) was a trade secret of Texas Instruments, made available to customers under non-disclosure agreement. This policy was likely instituted due to the cipher's non-standard design and small key size, which rendered it vulnerable to brute-force keysearch. In 2005, a group of students from the Johns Hopkins University Information Security Institute and RSA Laboratories reverse-engineered the cipher using an inexpensive Texas Instruments evaluation kit, through schematics of the cipher leaked onto Internet, and black-box techniques (i.e., querying transponders via the radio interface, rather than dismantling them to examining the circuitry). Once the cipher design was known, the team programmed several FPGA devices to perform brute-force key searches based on known challenge/response pairs. Using a single FPGA device, the team was able to recover a key from two known challenge/response pairs in approximately 11 hours (average case). With an array of 16 FPGA devices, they reduced this time to less than one hour. DST40 is a 200-round unbalanced Feistel cipher, in which L0 is 38 bits, and R0 is 2 bits. The key schedule is a simple linear feedback shift register, which updates every three rounds, resulting in some weak keys (e.g., the zero key). Although the cipher is potentially invertible, the DST protocol makes use of only the encipher mode. When used in the protocol with the 40–24-bit output truncation, the resulting primitive is more aptly described as a Message Authentication Code rather than an encryption function. Although a truncated block cipher represents an unusual choice for such a primitive, this design has the advantage of precisely bounding the number of collisions for every single key value. The DST40 cipher is one of the most widely used unbalanced Feistel ciphers in existence. The vulnerability exposed by the Hopkins team indicates potential security threats to millions of vehicles which are protected using DST-based immobilizer systems, and to the Exxon-Mobil Speedpass system. The ideal solution to this problem is to replace the DST transponder in these systems with a device provisioned with a more robust cryptographic circuit utilizing a longer key length. However, the cost of recalling these security systems is prohibitively high, and-- as of October 2005-- neither Texas Instruments, Exxon-Mobil or any vehicle manufacturer has announced such a recall. Currently the most effective protections against this attack rely on user vigilance, e.g., protecting transponder keys, auditing Speedpass invoices for fraud, and optionally using a metallic shield (such as aluminum foil) to prevent unauthorized scanning of DST tags. This vulnerability has also spawned the creation of the RSA Blocker Tag and RFID Blocking Wallets.
Views: 65 The Audiopedia
Entity Authentication and Symmetric Key Establishment, by Bart Preneel Authentication methods are based on something known, owned, biometric, location or evidence of trusted third party authentication. + A password is a case of something known. Passwords are a vulnerable, but cheap and convenient way of authenticating an entity. Several techniques to augment their effectiveness are in use including challenge-response and one-time passwords. + Secure devices such as smart cards and USB tokens often combine the 'owned' with the 'known', since secret keys are locked in the token with a password or PIN code. However, within the broad category of secure tokens, trustworthiness is variable, depending on whether keys can be extracted, passwords can be eavesdropped or the device can be tampered with. + Biometry identifies a person via physical characteristics. + Location is often used as the sole authentication factor, but is insecure given the relative ease of spoofing IP or MAC addresses. + Multi-factor authentication is stronger than single-factor. + The Kerberos protocol uses a key distribution-based authentication server. Service consumers must authenticate with a central server to obtain a secret session key with service providers. Such schemes require a single sign-on to access servers across a trust domain. While public key cryptography is well suited to entity authentication, performance constraints often mandate a symmetric algorithm for encrypting data passed between systems. Key establishment should be linked to authentication, so that a party has assurances that a key is only shared with the authenticated party. The Diffie-Hellman key agreement protocol underlies a host of current technologies such as STS (Station-to-Station protocol) and IKE. Learning objectives Gain insight into + entity authentication protocols, + the benefits and limitations of authentication factors, + key establishment protocols, + why and how to use authentication servers. This lecture was delivered by Bart Preneel in Leuven on Tuesday February 11th at SecAppDev 2014. Professor Bart Preneel heads the COSIC (COmputer Security and Industrial Cryptography) research group at KU Leuven. His main research area is information security with a focus on cryptographic algorithms and protocols as well as their applications to both computer and network security, and mobile communications. He teaches cryptology, network security and coding theory at the KU Leuven and was visiting professor at the Ruhr Universitaet Bochum (Germany), the T.U.Graz (Austria), the University of Bergen (Norway), and the Universiteit Gent (Belgium). In '93-'94 he was a research fellow at the University of California at Berkeley. He has taught intensive courses around the world. He undertakes industrial consulting (Mastercard International, S.W.I.F.T., Proton World International,...), and participates in the work of ISO/IEC JTC1/SC27/WG2. Professor Preneel is Vice President of the International Association for Cryptologic Research (IACR) and co-founder and chairman of LSEC vzw (Leuven Security Excellence Consortium).
Views: 1578 secappdev.org
The large number "RSA-129" posed a challenge experts said would take 40 quadrillion years to solve - but took 17. Featuring Ron Rivest, co-inventor of RSA... More links below... Our original RSA video (how it all works): https://youtu.be/M7kEpw1tn50 More from Ron from this interview (quantum computing): https://youtu.be/tX7e7CgWrvM More Ron Rivest on Numberphile: http://bit.ly/RonRivest Ron Rivest's own website: https://people.csail.mit.edu/rivest/ Public Key Cryptography on our sister channel, Computerphile: https://youtu.be/GSIDS_lvRv4 RSA-129: 114381625757888867669235779976146612010218296721242362562561842935706935245733897830597123563958705058989075147599290026879543541 Numberphile is supported by the Mathematical Sciences Research Institute (MSRI): http://bit.ly/MSRINumberphile We are also supported by Science Sandbox, a Simons Foundation initiative dedicated to engaging everyone with the process of science. NUMBERPHILE Website: http://www.numberphile.com/ Numberphile on Facebook: http://www.facebook.com/numberphile Numberphile tweets: https://twitter.com/numberphile Subscribe: http://bit.ly/Numberphile_Sub Videos by Brady Haran Patreon: http://www.patreon.com/numberphile Brady's videos subreddit: http://www.reddit.com/r/BradyHaran/ Brady's latest videos across all channels: http://www.bradyharanblog.com/ Sign up for (occasional) emails: http://eepurl.com/YdjL9
Views: 403749 Numberphile
This video explains what hashing is and how we can use it for authentication, attacks on this type of authentication, how to avoid this attacks.. enjoy صفحة الفيس بوك لو فيه اى سؤال بخصوص الفيديو وتابع فيديوهاتنا الجديده https://www.facebook.com/AmsheerTube
Views: 2412 Amsheer WaBasheer
If you like this video and want to support me, go this page for my donation crypto addresses: https://www.youtube.com/c/mobilefish/about This is part 34 of the IOTA tutorial. In this video series different topics will be explained which will help you to understand IOTA. It is recommended to watch each video sequentially as I may refer to certain IOTA topics explained earlier. In this tutorial I will explain in detail how the Time-based One-time Password algorithm works. This tutorial is not specific IOTA related. It is intended for developers who wants to understand how the Time-based One-time Password algorithm works. The Time-based One-time Password algorithm generates single use passwords, also known as tokens, which are only valid for a certain time period. Often this time period is 60 seconds. These generated tokens are based on a shared secret key. The Time-Based One-Time Password algorithm was published as RFC 6238 by the Internet Engineering Task Force (IETF). See: https://tools.ietf.org/html/rfc6238 In RFC 6238 a Java reference Time-based One-time Password algorithm can be found. See also: https://www.mobilefish.com/download/java/TOTP.java The Time-based One-time Password algorithm is an extension of the HMAC-Based One-Time Password (HOTP) algorithm, which was published as RFC 4226 by the IETF. The HMAC-Based One-Time Password defines an algorithm to create an one time password from a shared secret key and a counter. See: https://tools.ietf.org/html/rfc4226 When 2FA is enabled on the Trinity wallet, it first generates a shared secret key. You must write down this shared secret key and safely store it. Usually this shared secret key with additional information is embedded in a QR code which you can scan by a 2FA app such as the Google Authenticator. After the QR code is scanned the Google Authenticator generates a token which is a unique code, based on the shared secret key and the current time. Lets assume you are currently in Beijing (China). The local Beijing date and time is 4 December 2018, 20:24:20 (UTC+8). The date and time at that moment at 0 degree longitude meridian is 4 December 2018, 12:24:20. UTC stands for Coordinated Universal Time and is the time at the 0 degree longitude meridian (Prime Meridian). Convert this date and time (4 December 2018, 12:24:20) to Unix Epoch Time. Instead of Unix Epoch Time we can also say Unix Time (Tunix). Unix Epoch Time is the number of seconds that have elapsed since, 1 January 1970 00:00:00 UTC, not counting leap seconds. If the date and time at 0 degree longitude meridian is 4 December 2018, 12:24:20 than Tunix = 1543926260 sec Equation: N = floor(Tunix / ts) N = number of time steps which have been elapsed since Unix Epoch Time. floor = function which rounds a number downward to its nearest integer. Tunix = number of seconds that have elapsed since, 1 January 1970 00:00:00 UTC, not counting leap seconds. ts = time step. By default the time step is 30 sec. Convert the number of time steps (N) into a hexadecimal value. The hexadecimal value must have 16 hexadecimal characters (=8 bytes). If not, prepend with 0's. Convert the hexadecimal value into a 8 bytes array and assign this value to variable m (=message). Convert the shared secret key into a 20 bytes array and assign this value to variable K. The shared secret key is a randomly generated 20 bytes number which is base-32 encoded. For readability this key is divided in groups of 4 characters and all in lower case. More information about base-32, see Blockchain tutorial 31: https://youtu.be/Va8FLD-iuTg Calculate the HMAC hash using the HMAC-SHA1 algorithm. More information about HMAC, see Blockchain tutorial 30: https://youtu.be/emBgrRIyyWQ This HMAC hash size is 160 bits (=20 bytes). Get the last 4 bits of this hash value and get its integer value. In this example, the last 4 bits is 0xA which represents integer 10. This integer is called the offset. Starting from the offset, get the first 4 bytes from the HMAC hash. Apply a binary operation for each byte. Convert this binary value to an integer Calculate the Token = integer value % 10^n where n is the token size. If the token size is less than n, prefix with 0's. Every 30 seconds a new token is generated. But a token remains valid for 60 seconds. An online Time-based One-time Password generator can be found at: https://www.mobilefish.com/services/cryptocurrency/totp.html WARNING: DO NOT USE THIS TOOL TO GENERATE YOUR TOKENS. IT IS ONLY INTENDED FOR EDUCATIONAL, TEST OR DEMONSTRATION PURPOSES. Check out all my other IOTA tutorial videos: https://www.youtube.com/playlist?list=PLmL13yqb6OxdIf6CQMHf7hUcDZBbxHyza Subscribe to my YouTube channel: https://www.youtube.com/channel/UCG5_CT_KjexxjbgNE4lVGkg?sub_confirmation=1 The presentation used in this video tutorial can be found at: https://www.mobilefish.com/developer/iota/iota_quickguide_tutorial.html #mobilefish #howto #iota
Views: 882 Mobilefish.com
Database outsourcing is a common cloud computing paradigm that allows data owners to take advantage of its on-demand storage and computational resources. The main challenge is maintaining data confidentiality with respect to unauthorised parties. To overcome this problem, we propose a combination of triple randomized algorithms namely 3DES, AES, Blowfish. The data owner has the ability to select between the encryption methods which is suitable. As each of the algorithm takes different block size as input and also has various key size. Another problem which arises is the redundancy of data. When many copies of identical data are stored, the storage size decreases and large storage space is required. Here Data deduplication technique, which is used to identify duplicate files using hash code value method for better storage space. This allows a balance between the security of data and efficient query response as the queries are processed on encrypted data at the cloud server.
Views: 56 yours yogesh
This session was delivered at Sharkfest 2013 - UC Berkeley, CA Many people equate cryptography with confidentiality, but today we use cryptographic algorithms to validate authenticity, integrity and non-repudiation of information as well. In this session Larry will use Wireshark to sniff a number of SSL handshakes, using different browsers, to explain how algorithms are negotiated and keys exchanged. The hardest part about encryption, key management will also be discussed including a description of PKI standards, using Wireshark to illustrate certificate signing and revocation using both Certificate Revocation Lists (CRL) and the Online Certificate Status Protocol (OCSP). Larry started his IT career in 1984 as a technician for MicroAge, cutting his teeth on IBM PC-based networks and Netware 86. After four years in the 90s working for CGI/IBM as a senior network consultant designing and supporting IPX, SNA and TCP/IP-based network solutions, Larry founded InterNetwork Defense, an information security training and consulting company, where he currently teaches CEH, CISM and CISSP training classes. Larry is also the co-author of the cryptography section for the CEH official study guide.
Views: 6936 Chris Greer
Benjamin Fine (Fairfield University). Title: Password Security Using Combinatorial Group Theory Abstract. Joint with: Gilbert Baumslag and Doug Troeger. Over the past decade and a half there has been a concerted effort to apply combinatorial group theoretic methods to cryptographic protocols. In this talk we briefly explain how group theoretic techniques are applied to cryptology and then consider a method to apply group theoretic techniques to password security. Challenge response methods are increasingly used to enhance password security. In particular we present a very secure method for challenge response password verification using combinatorial group theory. This method, which relies on the group randomizer system, a subset of the MAGNUS computer algebra system, handles most of the present problems with challenge response systems. Theoretical security is based on several results in asymptotic group theory and these will be explained as well. For more information regarding the colloquium, please visit: https://sites.google.com/site/nyalg2/
Views: 109 Al Om
This implementation was made as a part of the course: Practical Cryptanalysis 2012, Technical University of Denmark. The project was about attacking a car key (fob) to recover the secret key used to unlock the car. Assuming the system is using 28-bit challenge-response, I built a rainbow table using a fixed challenge. Rainbow tables were implemented from scratch in Python. For the precomputation phase, 1,048,576 chains were used, each with a length of 1,024. The video shows the online phase, where the fob is given the fixed challenge, its response is captured and looked up in the rainbow table.
Views: 311 TriplePee
Part 13: We start looking into another challenge, Blocky's Revenge. I failed to reverse engineer this in the client, but had some success with the network packets. 🌴 Playlist: https://www.youtube.com/playlist?list=PLhixgUqwRTjzzBeFSHXrw9DnQtssdAwgG training_data: https://raw.githubusercontent.com/LiveOverflow/PwnAdventure3/master/tools/blocky/training_data to win these output bits have to be 0: [119,96,14,123,128,140,136,148,145,158,154,167,163,160,173] -=[ 🔴 Stuff I use ]=- → Microphone:* https://amzn.to/2LW6ldx → Graphics tablet:* https://amzn.to/2C8djYj → Camera#1 for streaming:* https://amzn.to/2SJ66VM → Lens for streaming:* https://amzn.to/2CdG31I → Connect Camera#1 to PC:* https://amzn.to/2VDRhWj → Camera#2 for electronics:* https://amzn.to/2LWxehv → Lens for macro shots:* https://amzn.to/2C5tXrw → Keyboard:* https://amzn.to/2LZgCFD → Headphones:* https://amzn.to/2M2KhxW -=[ ❤️ Support ]=- → per Video: https://www.patreon.com/join/liveoverflow → per Month: https://www.youtube.com/channel/UClcE-kVhqyiHCcjYwcpfj9w/join -=[ 🐕 Social ]=- → Twitter: https://twitter.com/LiveOverflow/ → Website: https://liveoverflow.com/ → Subreddit: https://www.reddit.com/r/LiveOverflow/ → Facebook: https://www.facebook.com/LiveOverflow/ -=[ 📄 P.S. ]=- All links with "*" are affiliate links. LiveOverflow / Security Flag GmbH is part of the Amazon Affiliate Partner Programm. #CTF #PwnAdventure
Views: 37763 LiveOverflow
Security+ Training Course Index: http://professormesser.link/sy0401 Professor Messer’s Course Notes: http://professormesser.link/sy0401cn Frequently Asked Questions: http://professormesser.link/faq - - - - - NTLM has been used to encrypt user authentication details in the Microsoft operating systems. In this video, you’ll learn about the history of NTLM and how the password information was stored in Windows. - - - - - Download entire video course: http://professormesser.link/401adyt Get the course on MP3 audio: http://professormesser.link/401vdyt Subscribe to get the latest videos: http://professormesser.link/yt Calendar of live events: http://www.professormesser.com/calendar/ FOLLOW PROFESSOR MESSER: Professor Messer official website: http://www.professormesser.com/ Twitter: http://www.professormesser.com/twitter Facebook: http://www.professormesser.com/facebook Instagram: http://www.professormesser.com/instagram Google +: http://www.professormesser.com/googleplus
Views: 29760 Professor Messer
All those information leaks revealing critical user data including passwords have risen the sensibility how important it is to keep your users account information safe. The safest way to be secure from those security incidents is, of course, not to store any passwords at all. And if you do not transmit any password over the wire, your system becomes even safe from sniffing attempts! A proven way to archive this it is defined with SRP, the Secure Remote Password protocol. This session shows you how to implement it and shares some experience from production systems using it.
Views: 1457 Devoxx Morocco
User Authentication Introduction to Passwords Based Authentication, Derived from Passwords, MD of Passwords Keywords: User Authentication Password Based Authentication Network Security Notes Computer Network Security Notes Something derived from passwords Problems with Clear Text Password Schemes Message Digest(MD) of Passwords
Views: 20791 Easy Engineering Classes
Electronic exchanges play an important role in the world financial system, acting as focal points where actors from across the world meet to trade with each other. But building an exchange is a difficult technical challenge, requiring high transaction rates, low, deterministic response times, fairness, and reliability. This talk looks at the question of how to design an exchange through the lens of JX, a crossing engine we built at Jane Street in the last two years. Performance plays an interesting role in this design, in that, although the end-to-end latency of the system is not important in and of itself, the ability of individual components of JX to handle messages rates in the 500k/sec range with latencies in the single-digit microseconds helped us build a replicated system that is both simple and robust.
Views: 41674 Jane Street
Using the greatest common divisor (GCD) to factorize the public modulo into the secret primes, so we can forge a RSA signature. Source for the rhme2 challenges: https://github.com/Riscure/Rhme-2016 -=[ 🔴 Stuff I use ]=- → Microphone:* https://amzn.to/2LW6ldx → Graphics tablet:* https://amzn.to/2C8djYj → Camera#1 for streaming:* https://amzn.to/2SJ66VM → Lens for streaming:* https://amzn.to/2CdG31I → Connect Camera#1 to PC:* https://amzn.to/2VDRhWj → Camera#2 for electronics:* https://amzn.to/2LWxehv → Lens for macro shots:* https://amzn.to/2C5tXrw → Keyboard:* https://amzn.to/2LZgCFD → Headphones:* https://amzn.to/2M2KhxW -=[ ❤️ Support ]=- → per Video: https://www.patreon.com/join/liveoverflow → per Month: https://www.youtube.com/channel/UClcE-kVhqyiHCcjYwcpfj9w/join -=[ 🐕 Social ]=- → Twitter: https://twitter.com/LiveOverflow/ → Website: https://liveoverflow.com/ → Subreddit: https://www.reddit.com/r/LiveOverflow/ → Facebook: https://www.facebook.com/LiveOverflow/ -=[ 📄 P.S. ]=- All links with "*" are affiliate links. LiveOverflow / Security Flag GmbH is part of the Amazon Affiliate Partner Programm. #CTF #Cryptography
Views: 46117 LiveOverflow
Saturday, July 22, 2006: 7:00 pm (Area "B"): This lecture will show how to construct advanced cryptographic protocols. Beginning with a set of requirements for a communications protocol that includes immunity from replay attacks, traffic analysis resistance, and resiliency against partial compromise, the audience will be shown how a naive protocol can be iteratively improved into a protocol satisfying those requirements. Hosted by J. Salvatore Testa II
Views: 102 Channel2600
Configuring Password Authentication Protocol [PAP] & Challenge Handshake Authentication Protocol [CHAP] ----------------------------------------------------------------------------------------------------------- Password authentication protocol (PAP) and challenge handshake authentication protocol (CHAP) are both used to authenticate PPP sessions and can be used with many VPNs. Basically, PAP works like a standard login procedure; the remote system authenticates itself to the using a static user name and password combination. The password can be encrypted for additional security, but PAP is subject to numerous attacks. In particular, since the information is static, it is subject to password guessing as well as snooping. CHAP takes a more sophisticated and secure approach to authentication by creating a unique challege phrase (a randomly generated string) for each authentication. The challenge phrase is combined with device host names using oneway hashing functions to authenticate in way where no static secret information is ever transmitted over the wire. Because all transmitted information is dymanic, CHAP is significantly more robust than PAP. For More Details - https://en.wikipedia.org/wiki/Challenge-Handshake_Authentication_Protocol https://searchnetworking.techtarget.com/answer/Which-is-most-secure-CHAP-or-PAP
Views: 100 Maddy’s World
Encryption 101 begins with understanding the terminology and mechanisms. This week we're breaking down encryption in the context of SSH - from symmetric and asymmetric to block and stream ciphers. All that and more, this time on Hak5. If you're into Hak5 you'll love our new show by hosts Darren Kitchen and Shannon Morse. Check out http://www.revision3.com/haktip Whether you're a beginner or a pro, http://www.revision3.com/haktip is essential viewing for current and aspiring hackers, computer enthusiasts, and IT professionals. With a how-to approach to all things Information Technology, HakTip breaks down the core concepts, tools, and techniques of Linux, Wireless Networks, Systems Administration, and more. And let's not forget to mention that you can follow us on http://www.twitter.com/hak5 and http://www.facebook.com/technolust, http://revision3.com/hak5/follow to the show and get all your Hak5 goodies, including the infamous wifi-pineapple over at http://hakshop.com . If you have any questions or suggestions please feel free to contact us at [email protected]
Views: 18350 Hak5
Your views, likes, comments, shares and streams are analysed by The ShareSpace data scientists to work out which artist has had the best response to their content throughout the 30 days. Weekly results will be revealed every Sunday on The ShareSpace YouTube channel! THE TECHNICAL STUFF: Voting tally of the social engagement for the ShareSpace algorithm is enabled by Ansible and confirmed by Cadreon analytics and data science. For more info email [email protected] ♫♫♫ The ShareSpace is a music collaboration project with daily episodes and weekly music releases. 30 days. 8 artists. 1 ShareSpace. SUBSCRIBE NOW → http://bit.ly/TheShareSpace SEE MORE OF THE SHARESPACE AT OUR SOCIALS: Facebook → www.Facebook.com/TheShareSpace Twitter → www.Twitter.com/TheShareSpace Instagram → www.Instagram.com/TheShareSpace Snapchat → Search ‘thesharespace’ The ShareSpace: Create. Collaborate. Share! www.thesharespace.com [email protected]
Views: 1461 The ShareSpace
Viewers like you help make PBS (Thank you 😃) . Support your local PBS Member Station here: https://to.pbs.org/donateinfi Symmetric keys are essential to encrypting messages. How can two people share the same key without someone else getting a hold of it? Upfront asymmetric encryption is one way, but another is Diffie-Hellman key exchange. This is part 3 in our Cryptography 101 series. Check out the playlist here for parts 1 & 2: https://www.youtube.com/watch?v=NOs34_-eREk&list=PLa6IE8XPP_gmVt-Q4ldHi56mYsBuOg2Qw Tweet at us! @pbsinfinite Facebook: facebook.com/pbsinfinite series Email us! pbsinfiniteseries [at] gmail [dot] com Previous Episode Topology vs. “a” Topology https://www.youtube.com/watch?v=tdOaMOcxY7U&t=13s Symmetric single-key encryption schemes have become the workhorses of secure communication for a good reason. They’re fast and practically bulletproof… once two parties like Alice and Bob have a single shared key in hand. And that’s the challenge -- they can’t use symmetric key encryption to share the original symmetric key, so how do they get started? Written and Hosted by Gabe Perez-Giz Produced by Rusty Ward Graphics by Ray Lux Assistant Editing and Sound Design by Mike Petrow and Meah Denee Barrington Made by Kornhaber Brown (www.kornhaberbrown.com) Thanks to Matthew O'Connor, Yana Chernobilsky, and John Hoffman who are supporting us on Patreon at the Identity level! And thanks to Nicholas Rose, Jason Hise, Thomas Scheer, Marting Sergio H. Faester, CSS, and Mauricio Pacheco who are supporting us at the Lemma level!
Views: 53870 PBS Infinite Series
Clickbait title. Just a bit of brain food. Games, licenses and many other things depend on a good time source. But where does the time come from and should you trust it? -=[ 🔴 Stuff I use ]=- → Microphone:* https://amzn.to/2LW6ldx → Graphics tablet:* https://amzn.to/2C8djYj → Camera#1 for streaming:* https://amzn.to/2SJ66VM → Lens for streaming:* https://amzn.to/2CdG31I → Connect Camera#1 to PC:* https://amzn.to/2VDRhWj → Camera#2 for electronics:* https://amzn.to/2LWxehv → Lens for macro shots:* https://amzn.to/2C5tXrw → Keyboard:* https://amzn.to/2LZgCFD → Headphones:* https://amzn.to/2M2KhxW -=[ ❤️ Support ]=- → per Video: https://www.patreon.com/join/liveoverflow → per Month: https://www.youtube.com/channel/UClcE-kVhqyiHCcjYwcpfj9w/join -=[ 🐕 Social ]=- → Twitter: https://twitter.com/LiveOverflow/ → Website: https://liveoverflow.com/ → Subreddit: https://www.reddit.com/r/LiveOverflow/ → Facebook: https://www.facebook.com/LiveOverflow/ -=[ 📄 P.S. ]=- All links with "*" are affiliate links. LiveOverflow / Security Flag GmbH is part of the Amazon Affiliate Partner Programm.
Views: 183441 LiveOverflow