In cryptography, the Cellular Message Encryption Algorithm (CMEA) is a block cipher which was used for securing mobile phones in the United States. CMEA is one of four cryptographic primitives specified in a Telecommunications Industry Association (TIA) standard, and is designed to encrypt the control channel, rather than the voice data. In 1997, a group of cryptographers published attacks on the cipher showing it had several weaknesses which give it a trivial effective strength of a 24-bit to 32-bit cipher.Some accusations were made that the NSA had pressured the original designers into crippling CMEA, but the NSA has denied any role in the design or selection of the algorithm. The and ciphers are derived from CMEA. CMEA is described in U.S. Patent 5,159,634. It is byte-oriented, with variable block size, typically 2 to 6 bytes. The key size is only 64 bits. Both of these are unusually small for a modern cipher. The algorithm consists of only 3 passes over the data: a non-linear left-to-right diffusion operation, an unkeyed linear mixing, and another non-linear diffusion that is in fact the inverse of the first. The non-linear operations use a keyed lookup table called the T-box, which uses an unkeyed lookup table called the CaveTable. The algorithm is self-inverse; re-encrypting the ciphertext with the same key is equivalent to decrypting it. CMEA is severely insecure. There is a chosen-plaintext attack, effective for all block sizes, using 338 chosen plaintexts. For 3-byte blocks (typically used to encrypt each dialled digit), there is a known-plaintext attack using 40 to 80 known plaintexts. For 2-byte blocks, 4 known plaintexts suffice. The "improved" CMEA, CMEA-I, is not much better: chosen-plaintext attack of it requires less than 850 plaintexts in its adaptive version. (Wikipedia).
Network Security: Classical Encryption Techniques
Fundamental concepts of encryption techniques are discussed. Symmetric Cipher Model Substitution Techniques Transposition Techniques Product Ciphers Steganography
From playlist Network Security
One Time Pad - Applied Cryptography
This video is part of an online course, Applied Cryptography. Check out the course here: https://www.udacity.com/course/cs387.
From playlist Applied Cryptography
Message Authentication Codes: Part 1
Message Authentication MACs based on Hash Functions: HMAC MACs based on Block Ciphers: DAA and CMAC Authenticated Encryption: CCM and GCM Pseudorandom Number Generation Using Hash Functions and MACs
From playlist Network Security
Message Authentication Codes: Part 2
Message Authentication MACs based on Hash Functions: HMAC MACs based on Block Ciphers: DAA and CMAC Authenticated Encryption: CCM and GCM Pseudorandom Number Generation Using Hash Functions and MACs
From playlist Network Security
Cryptanalysis of Classical Ciphers
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
28C3: Cellular protocol stacks for Internet (en)
For more information visit: http://bit.ly/28C3_information To download the video visit: http://bit.ly/28C3_videos Playlist 28C3: http://bit.ly/28C3_playlist Speaker: Harald Welte Almost everyone uses the packet oriented transmission modes of cellular networks. However, unlike TCP/I
From playlist 28C3: Behind Enemy Lines
Pseudorandom Number Generation and Stream Ciphers
Fundamental concepts of Pseudorandom Number Generation are discussed. Pseudorandom Number Generation using a Block Cipher is explained. Stream Cipher & RC4 are presented.
From playlist Network Security
Understanding Encryption! | ICT #9
The words encryption and decryption are quite familiar to us. You might have already come across these technical words in this video series, as well as in your daily life. What is encryption, and why is it needed? By the end of this video you will also understand the magic that prime numbe
From playlist Internet & Telecommunication Technology
What We've Learned from NKS Chapter 7: Mechanisms in Programs and Nature
In this episode of "What We've Learned from NKS", Stephen Wolfram is counting down to the 20th anniversary of A New Kind of Science with [another] chapter retrospective. If you'd like to contribute to the discussion in future episodes, you can participate through this YouTube channel or th
From playlist Science and Research Livestreams
Countermeasures - Applied Cryptography
This video is part of an online course, Applied Cryptography. Check out the course here: https://www.udacity.com/course/cs387.
From playlist Applied Cryptography
Network Security, Part 2 : Public Key Encryption
Fundamental concepts of public key encryption are discussed. RSA encryption method explained with an example. Confidentiality of message is presented.
From playlist Cryptography, Security
DEFCON 13: End-to-End Voice Encryption over GSM: A Different Approach
Speakers: Wesley Tanner Nick Lane-Smith Where is end-to-end voice privacy over cellular? What efforts are underway to bring this necessity to the consumer? This discussion will distill for you the options available today, and focus on current research directions in technologies for th
From playlist DEFCON 13
DEFCON 13: From Cyberspace to Hyperspace
Speaker: Sam Thigpen For more information visit: http://bit.ly/defcon13_information To download the video visit: http://bit.ly/defcon13_videos
From playlist DEFCON 13
What We've Learned from NKS Chapter 10: Processes of Perception and Analysis
In this episode of "What We've Learned from NKS", Stephen Wolfram is counting down to the 20th anniversary of A New Kind of Science with [another] chapter retrospective. If you'd like to contribute to the discussion in future episodes, you can participate through this YouTube channel or th
From playlist Science and Research Livestreams
IMS Public Lecture: Are Quantum Computers The Next Generation Of Supercomputers?
Reinhard Werner, Technische Universität Braunschweig, Germany
From playlist Public Lectures
Computer Networking Course - Network Engineering [CompTIA Network+ Exam Prep]
This full college-level computer networking course will prepare you to configure, manage, and troubleshoot computer networks. It will also help you prepare for CompTIA's Network+ exam. This course was developed by Brian Ferrill, an instructor at Edmonds Community College. ⭐️ Course Conte
From playlist Networks
An informal introduction to cryptography. Part of a larger series teaching programming at http://codeschool.org
From playlist Cryptography
29C3: The future of protocol reversing and simulation applied on ZeroAccess botnet (EN)
Speakers: Frédéric Guihéry | Georges Bossert Mapping your enemy Botnet with Netzob Have you ever been staring for nights at binary or hexadecimal data flows extracted from an USB channel? Don't you remember yourself searching for some patterns and similarities in this fuc*g mess of zeros
From playlist 29C3: Not my department