Stream ciphers

Keystream

In cryptography, a keystream is a stream of random or pseudorandom characters that are combined with a plaintext message to produce an encrypted message (the ciphertext). The "characters" in the keystream can be bits, bytes, numbers or actual characters like A-Z depending on the usage case. Usually each character in the keystream is either added, subtracted or XORed with a character in the plaintext to produce the ciphertext, using modular arithmetic. Keystreams are used in the one-time pad cipher and in most stream ciphers. Block ciphers can also be used to produce keystreams. For instance, CTR mode is a block mode that makes a block cipher produce a keystream and thus turns the block cipher into a stream cipher. (Wikipedia).

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HAR 2009: Classic Mistakes 4/7

Clip 4 Speaker: Roel Verdult Mistakes made with the Mifare Classic This lecture gives a broad overview of the vulnerabilities that exists in MIFARE Classic products and the way they are used by system integrators. For more information go to: https://har2009.org/program/events/36

From playlist Hacking at Random (HAR) 2009

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26C3: Legic Prime: Obscurity in Depth 3/7

Clip 3/7 Speakers: Henryk Plötz ,Karsten Nohl Legic Prime is an artifact from the time when proprietary cryptography in RFID was considered secure enough. We will demonstrate a break for basically any aspect of Legic Prime's claimed security features. If you rely on Legic Prime's sec

From playlist 26C3: Here be dragons day 2

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26C3: Reverse-Engineering DisplayLink devices 2/4

Clip 2/4 Speaker: Florian Echtler USB to DVI for Hackers DisplayLink produces nice, useful USB graphics adapters. Unfortunately, they had no real Linux support. In this talk, we'll describe how we first reverse-engineered the encryption and basic protocol, prompting DisplayLink to ac

From playlist 26C3: Here be dragons day 2

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26C3: DECT (part II) 5/7

Clip 5/7 Speaker: Erik Tews What has changed in DECT security after one year After dedected.org was published on 25C3, lots has changed in DECT security. For more information go to: http://events.ccc.de/congress/2009/Fahrplan/events/3648.en.html

From playlist 26C3: Here be dragons day 3

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How to Build a KeyLogger in C++ | Introduction | #C | #programming

Don’t forget to subscribe! This project series is about creating a Keylogger in C++. A KeyLogger is a program that can capture every key or click that is pressed on the computer asynchronously. In order to get useful information, we will learn how to erase the cache, build the keylogger

From playlist Build A KeyLogger In C++

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How to Build a KeyLogger in C++ | Session 18 | #C | #programming

Don’t forget to subscribe! This project series is about creating a Keylogger in C++. A KeyLogger is a program that can capture every key or click that is pressed on the computer asynchronously. In order to get useful information, we will learn how to erase the cache, build the keylogger

From playlist Build A KeyLogger In C++

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How to Build a KeyLogger in C++ | Session 10| #C | #programming

Don’t forget to subscribe! This project series is about creating a Keylogger in C++. A KeyLogger is a program that can capture every key or click that is pressed on the computer asynchronously. In order to get useful information, we will learn how to erase the cache, build the keylogger

From playlist Build A KeyLogger In C++

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How to Build a KeyLogger in C++ | Session 11| #C | #programming

Don’t forget to subscribe! This project series is about creating a Keylogger in C++. A KeyLogger is a program that can capture every key or click that is pressed on the computer asynchronously. In order to get useful information, we will learn how to erase the cache, build the keylogger

From playlist Build A KeyLogger In C++

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25c3: An introduction to new stream cipher designs

Speaker: Tor E. Bjørstad Turning data into line noise and back Even with "nothing to hide", we want to protect the privacy of our bits and bytes. Encryption is an important tool for this, and stream ciphers are a major class of symmetric-key encryption schemes. Algorithms such as RC4 (us

From playlist 25C3: Nothing to hide

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How to Build a KeyLogger in C++ | Session 12| #C | #programming

Don’t forget to subscribe! This project series is about creating a Keylogger in C++. A KeyLogger is a program that can capture every key or click that is pressed on the computer asynchronously. In order to get useful information, we will learn how to erase the cache, build the keylogger

From playlist Build A KeyLogger In C++

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How to Build a KeyLogger in C++ | Session 20 | #C | #programming

Don’t forget to subscribe! This project series is about creating a Keylogger in C++. A KeyLogger is a program that can capture every key or click that is pressed on the computer asynchronously. In order to get useful information, we will learn how to erase the cache, build the keylogger

From playlist Build A KeyLogger In C++

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How to Build a KeyLogger in C++ | Session 13| #C | #programming

Don’t forget to subscribe! This project series is about creating a Keylogger in C++. A KeyLogger is a program that can capture every key or click that is pressed on the computer asynchronously. In order to get useful information, we will learn how to erase the cache, build the keylogger

From playlist Build A KeyLogger In C++

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26C3: DECT (part II) 3/7

Clip 3/7 Speaker: Erik Tews What has changed in DECT security after one year After dedected.org was published on 25C3, lots has changed in DECT security. For more information go to: http://events.ccc.de/congress/2009/Fahrplan/events/3648.en.html

From playlist 26C3: Here be dragons day 3

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26C3: Reverse-Engineering DisplayLink devices 1/4

Clip 1/4 Speaker: Florian Echtler USB to DVI for Hackers DisplayLink produces nice, useful USB graphics adapters. Unfortunately, they had no real Linux support. In this talk, we'll describe how we first reverse-engineered the encryption and basic protocol, prompting DisplayLink to ac

From playlist 26C3: Here be dragons day 2

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How to Build a KeyLogger in C++ | Session 19 | #C | #programming

Don’t forget to subscribe! This project series is about creating a Keylogger in C++. A KeyLogger is a program that can capture every key or click that is pressed on the computer asynchronously. In order to get useful information, we will learn how to erase the cache, build the keylogger

From playlist Build A KeyLogger In C++

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How to Build a KeyLogger in C++ | Session 15 | #C | #programming

Don’t forget to subscribe! This project series is about creating a Keylogger in C++. A KeyLogger is a program that can capture every key or click that is pressed on the computer asynchronously. In order to get useful information, we will learn how to erase the cache, build the keylogger

From playlist Build A KeyLogger In C++

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Stream Ciphers (Contd...2)

Cryptography and Network Security by Prof. D. Mukhopadhyay, Department of Computer Science and Engineering, IIT Kharagpur. For more details on NPTEL visit http://nptel.iitm.ac.in

From playlist Computer - Cryptography and Network Security

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Securing Stream Ciphers (HMAC) - Computerphile

Bit flipping a stream cipher could help you hit the Jackpot! But not with HMAC. Dr Mike Pound explains. Correction : "pseudo" is spelled incorrectly on the graphic. http://www.facebook.com/computerphile https://twitter.com/computer_phile This video was filmed and edited by Sean Riley.

From playlist Cryptography on Numberphile and Computerphile

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How to Build a KeyLogger in C++ | Session 14 | #C | #programming

Don’t forget to subscribe! This project series is about creating a Keylogger in C++. A KeyLogger is a program that can capture every key or click that is pressed on the computer asynchronously. In order to get useful information, we will learn how to erase the cache, build the keylogger

From playlist Build A KeyLogger In C++

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Black Hat USA 2010: Attacking Phone Privacy 4/5

Speaker: Karsten Nohl Our most popular phone technologies use decade-old proprietary cryptography. GSM's 64bit A5/1 cipher, for instance, is vulnerable to time memory trade-offs but commercial cracking hardware costs hundreds of thousands of dollars. We discuss how cryptographic improveme

From playlist BH USA 2010 - PRIVACY

Related pages

Plaintext | Stream cipher | One-time pad | Modular arithmetic | Pseudorandomness | Block cipher | Randomness | Byte | Bit | Cryptography