Successfully reported this slideshow.
We use your LinkedIn profile and activity data to personalize ads and to show you more relevant ads. You can change your ad preferences anytime.

Digital certificates and information security


Published on

Digital certificates ensures secure transactions over internet. This presentation is about information security and secure online transactions through digital certificates.


Published in: Technology
  • Be the first to comment

Digital certificates and information security

  1. 1. Digital Certificates
  2. 2. Introduction What is cryptography? The art of secret writing • Cryptosystems • keys
  3. 3. Problem Problem: How does Alice know that the public key she received is really Bob’s public key?
  4. 4. Digital Certificate • Electronic counterparts to driver licenses, passports • Prove your identity or right to access information or services online • Bind an identity to a pair of electronic keys • Provide a more complete security solution • Role of Certification Authority (CA)
  5. 5. Digital Certificates • Structure of Digital Certificate – Owner's public key – Owner's name – Expiration date of the public key – Name of the issuer (the CA that issued the Digital Certificate) – Serial number of the Digital Certificate – Digital signature of the issuer • Defined by CCITT X.509 international standard
  6. 6. Digital Certificates • Provide support for public key cryptography (PKC) • Digital certificates contain the public key of the entity • It rely on PKC for their own authentication • Used on handheld devices, mobile phones, on portable cards, smart cards
  7. 7. public key infrastructure (PKI) A public key infrastructure (PKI) consists of the components necessary to securely distribute public keys It consists of: – Certificates – Certificate authorities (CAs) – A repository for retrieving certificates – A method for revoking certificates – A method of evaluating a chain of certificates
  8. 8. Public Key Infrastructures (PKIs) • To use public key methods, an organization must establish a comprehensive Public Key Infrastructure (PKI) – A PKI automates most aspects of using public key encryption and authentication – Uses a PKI Server
  9. 9. Public Key Infrastructures (PKIs) • PKI Server Creates Public Key-Private Key Pairs – Distributes private keys to applicants securely – Often, private keys are embedded in delivered software PKI Server Private Key
  10. 10. Public Key Infrastructures (PKIs) • PKI Server Provides Certificate Revocation list (CRL) Checks – Distributes digital certificates to verifiers – Checks certificate revocation list before sending digital certificates PKI Server Digital Certificate
  11. 11. Public Key Infrastructures (PKIs) • CRL Checks – If applicant gives verifier a digital certificate, – The verifier must check the certificate revocation list PKI Server OK? OK or Revoked CRL
  12. 12. Generating the digital certificate
  13. 13. Digital Certificate : Example
  14. 14. Use of Digital Certificates • Electronic transactions – E-mail – Electronic commerce – Groupware – Electronic funds transfers • Netscape's Enterprise Server
  15. 15. Message Encryption Message Decryption Use of Digital Certificates
  16. 16. Need of Digital Certificates • Proper Privacy and Security • Trust • Special safeguards • Assuring the identity of all parties • To provide legitimate content
  17. 17. Digital Certificate Services • Services – Issuing – Revocation – Status services • Types of Digital Certificates – Server – Developer (For softwares) – personal
  18. 18. Digital Signature • Function as hand written signature electronically • Non repudiated • Enable "authentication" of digital messages
  19. 19. DC used for Digital signature and Encryption
  20. 20. DC used for Digital signature and Decryption
  21. 21. References •