1. James Higdon, Sameer Sherwani
Identity Based
 Cryptography
James Higdon, Sameer Sherwani
CpSc 624/424

2. Overview Type of encryption mechanisms Types of encryptions
Basic Identity based encryption
Advantages
Disadvantages
Applications
-need for encryption
  -communication
     - s
  -sensitive information
-types of encryption
  -symmetric, non, public, private
     -types of public key
        -RSA
        -IBE is a public key encryption

3.    Encryption
 - process of transforming information(plaintext) using a cipher (algorithm) to ciphertext. 

4. Types of cryptographic mechanisms
 Key Authentication 
One way hash functions: MD5, SHA
Digital signatures: Verify user: DSA  
 Key exchange
 key distribution: Diffi-Hellman 
 Key generation
 Block Ciphers: DES/AES; ATM, passwords

5. Types of keys(ciphers)
Symmetric keys
Traditional asymmetric keys 
Identity-based asymmetric keys
 Common public-key Algorithms 
( RSA, Elliptic curve, Discrete logarithm based) 
 Explain difference between traditional and Identity based asymmetric keys

6. Symmetric Encryption

7. Asymmetric Encryption (Public Key Infrastructure - PKI)

8. ID-based Encryption

9. Identity based Encryption(IBE)
  "identity-based"...  mainly about keys
 The major differences between an identity-based 
system and a traditional system are
 How to authenticate the key
 How to distribute the key
 How to use the key 

10. Identity based Encryption(IBE)
A public-key encryption system in which an arbitrary string can be used as the public key.
Any personal information:
An address, a photo, and a postal address, etc
Any terms and conditions, such as a time etc
Developed by Adi Shamir in 1984
However, the encryption schemes were not fully used or created until 2001.

11. How it works
Private Keys are generated by a third party Private Key Generator (PKG)
PKG publishes a public master key and retains the private master key
With the correct ID, users can contact the PKG to obtain the private key
This way, messages may be encrypted without a prior distribution of keys between individuals 

13. Advantages Reduces the complexity of the encryption process
No certificates needed. A recipient's public key is derived from his identity.
No pre-enrollment required.
Keys expire, so they don't need to be revoked. In a traditional public-key system, keys must be revoked if compromised.
Less vulnerable to spam.
Enables postdating of messages for future decryption.
Enables automatic expiration, rendering messages unreadable after a certain date.

14. Disadvantages
Requires a centralized server. IBE's centralized approach implies that some keys must be created and held in escrow -- and are therefore at greater risk of disclosure.
Requires a secure channel between a sender or recipient and the IBE server for transmitting the private key.

15. Real-World Application
Voltage Security provide Identity-Based Encryption for s
IBE Toolkit available to those who would like to use the encryption services