Information theoretic security | Wikipedia audio article
Channel: wikipedia tts
Date: 29/12/2018

This is an audio version of the Wikipedia Article:
https://en.wikipedia.org/wiki/Information-theoretic_security


00:04:44 1 Physical layer encryption
00:09:41 2 Unconditional security
00:10:49 3 See also



Listening is a more natural way of learning, when compared to reading. Written language only began at around 3200 BC, but spoken language has existed long ago.

Learning by listening is a great way to:
- increases imagination and understanding
- improves your listening skills
- improves your own spoken accent
- learn while on the move
- reduce eye strain

Now learn the vast amount of general knowledge available on Wikipedia through audio (audio article). You could even learn subconsciously by playing the audio while you are sleeping! If you are planning to listen a lot, you could try using a bone conduction headphone, or a standard speaker instead of an earphone.

Listen on Google Assistant through Extra Audio:
https://assistant.google.com/services/invoke/uid/0000001a130b3f91
Other Wikipedia audio articles at:
https://www.youtube.com/results?search_query=wikipedia+tts
Upload your own Wikipedia articles through:
https://github.com/nodef/wikipedia-tts
Speaking Rate: 0.7544785154832414
Voice name: en-US-Wavenet-C


"I cannot teach anybody anything, I can only make them think."
- Socrates


SUMMARY
=======
Information-theoretic security is a cryptosystem whose security derives purely from information theory, so that the system cannot be broken even if the adversary has unlimited computing power. The adversary does not have enough information to break the encryption, and so the cryptosystem is considered cryptanalytically unbreakable.
An encryption protocol with information-theoretic security does not depend for its effectiveness on unproven assumptions about computational hardness. Such a protocol is not vulnerable to future developments in computer power such as quantum computing. An example of an information-theoretically secure cryptosystem is the one-time pad. The concept of information-theoretically secure communication was introduced in 1949 by American mathematician Claude Shannon, the inventor of information theory, who used it to prove that the one-time pad system was secure.  Information-theoretically secure cryptosystems have been used for the most sensitive governmental communications, such as diplomatic cables and high-level military communications, because of the great efforts enemy governments expend toward breaking them.
Perfect security is a special case. For an encryption algorithm, if there is ciphertext produced that uses it, no information about the plaintext is provided without knowledge of the key. If E is a perfectly secure encryption function, for any fixed message m, there must be, for each ciphertext c, at least one key k such that 
  
    
      
        c
        =
        
          E
          
            k
          
        
        (
        m
        )
      
    
    {\displaystyle c=E_{k}(m)}
  . It has been proved that any cipher with the perfect secrecy property must use keys with effectively the same requirements as one-time pad keys.It is common for a cryptosystem to leak some information but nevertheless maintain its security properties even against an adversary that has unlimited computational resources. Such a cryptosystem would have information theoretic but not perfect security. The exact definition of security would depend on the cryptosystem in question.
There are a variety of cryptographic tasks for which information-theoretic security is a meaningful and useful requirement. A few of these are:

Secret sharing schemes such as Shamir's are information-theoretically secure (and also perfectly secure) in that having less than the requisite number of shares of the secret provides no information about the secret.
More generally, secure multiparty computation protocols often have information-theoretic security.
Private information retrieval with multiple databases can be achieved with information-theoretic privacy for the user's query.
Reductions between cryptographic primitives or tasks can often be achieved information-theoretically. Such reductions are important from a theoretical perspective because they establish that primitive 
  
    
      
        Π
      
    
    {\displaystyle \Pi }
   can be realized if primitive 
  
    
      
        
          Π
          ′
        
      
    
    {\displaystyle \Pi '}
   can be realized.
Symmetric encryption can be constructed under an information-theoretic notion of security called entropic security, which assumes that the adversary knows almost nothing about the message being sent. The goal here is to hide all functions of the plaintext rather than all information about it.
Quantum cryptography is largely part of information-theoretic cryptography.