انسان در طبیعت حقیقت را جستجو می کند و در خویشتن

1. انسان در طبیعت حقیقت را جستجو می کند و در خویشتن خوبی را

2. بسم الله الرحمن الرحيم خدایا به من بیاموز : زبانم ذکر سکوتم فکر و نگاهم عبادت باشد.

3. PKI (Public key Infrastructure) Ali Miravandi • Ali_Miravandi@yahoo.com

4. Network

5. Network Security Solution Bank Online Internet

6. Network Security Solution Internet Very Good Hi Bob Good Morning At 9:00 AM Smith Hi Bob Good Night At 9:00 PM Smith OK I see Smith At 9:00 PM Smith Bob

7. Server Verify Username & Password. OK. OK. Success in Login NO Login User name: ALI Password: 123 User name: ALI Password: 123 Hack User name: ALI Password: 123 User name: ALI Password: 123

8. What PKI Provides Authentication: شناسایی Integrity: بی نقصی Anti-Reply: ضد پاسخ Non-Repudiation: انکار نکردن Confidentiality: اطمینان

9. Cryptography is THE basis for PKI There are three types of cryptosystems - Symmetric Key( sometimes called secret key) - ASymmetric Key( Public & Private key) - Message Digest

10. Symmetric Key Transfer Recieve Bob Smith 1010000111010101 Data Tranfer Data Encreypt Data Decrypt Public Network

11. Private Key Public Key Public Key Private Key ASymmetric Key Smith Bob Data Encrypt Data Tranfer Data Decrypt Public Network

12. Data Data Message Digest Hi My name is Bob How are you? Computer Variable Input Ds??dcsdcs#djfh!dkj Hash Value A$Dhi?ks&vk*dkjvb Fix Output Hash Algorithm

13. Data Data Digital Signature Smith Sara Public Key Sara

14. Data Data Digital Signiture Smith Sara Private Key Public Key If hash values match, data came from the owner of the private key and is valid Hash Value Hash Value

15. Thank You First Conference on Security Network Elmi sanati University of Mashhad, 2009