Near Field Authentication

Near Field Authentication

  • Introduction
    • Near Field Communication (NFC) system provide smartphones the ability to let two smart phones communicate with each other only when they are within a very small distance, usually a few centimeters. 
    • For example, the Google wallet system uses NFC systems to establish the connection between a user and a checkout machine. 
    • For example, the secure file transfer between two smartphones. It uses NFC systems to first exchange a cryptographic key and then transfer encrypted files over wireless local area network (WLN). 
  • Authenticate whether two smartphones stay closely to each other. 
    • It is natural to use NFC chips, however it is not available on many smart phones. 
    • Another approach proposed by Li et al in ICC 2013.
      • Put two smart phones side by side and let the use slide his finger across the two smartphone screens. 
      • When two smart phones are in near field, their designed system will generate the same cryptographic key for both.
      • The key can be used by another system to carry out confidential communications. 
  • Background
    • The Diffie–Hellman key exchange method allows two parties that have no prior knowledge of each other to jointly establish a shared secret key over an insecure channel. This key can then be used to encrypt subsequent communications using a symmetric key cipher.
      • Alice and Bob agree to use a modulus p = 23 and base g = 5 
      • They have their own secret integer
      • They send message (g^theirSecret) mod p
      • They descrypt the message (message)^their own secret, the results would be the same. Thus they can established a shared key.
    • Man in the middle attack
      • The attacker secretly relays and possibly alters the communication between two parties who believe they are directly communicating with each other
Reference
[1] http://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=6655633

Leave a Reply

Your email address will not be published. Required fields are marked *

*