100 likes | 270 Views
An In-Depth Examination of PKI. Strengths, Weaknesses and Recommendations. Encryption. Hiding the intent or meaning of a message Complex mathematical algorithms Should be unbreakable Claude Shannon, the Father of Information Theory. Shared and Public Key. Shared Key Encryption
E N D
An In-Depth Examination of PKI Strengths, Weaknesses and Recommendations
Encryption • Hiding the intent or meaning of a message • Complex mathematical algorithms • Should be unbreakable • Claude Shannon, the Father of Information Theory
Shared and Public Key • Shared Key Encryption • Same Key for Encryption/Decryption • Key dispatched in secure manner • DES, 3DES, AES • Public Key • Key Generation • Encrypt with Public Key • Decrypt with Private Key • RSA
Digital Signatures and Certificates • Digital Signature • Create Message Digest (MD5, SHA1) • Sign Hash • Append Signed Hash to Message • Verify by hashing message, public key decrypt of message • Digital Certificate • Public Key, Authority Signature, Key Information • Mutually trusted authority signature
What is PKI? • Infrastructure • End Entity • Certificate Authority • Registration Authority • Directory (X.500, LDAP) • CRL Repository • PKI not itself a solution – SSL/TLS
Issues with PKI • Key Management • CRL Distribution • Trust
Key Management • Where? • On laptops, desktops? • Centrally located (protected)? • Multiple certificates? • Backing up Keys – why? • Smartcards • Tamper-resistant • Work with magnetic-stripe cards • Portable, holds multiple keys
Certificate Revocation Lists • Performance • DoS • Frequent Information • Solutions • Segmenting • Over distribution • Online Certificate Status Protocol (OCSP) • Validity real-time • Expensive
Trust • How/Why do we Trust CAs? (CSPs) • Do we read/view certificates? • Authentication not authorization • Usability and Trust • “Web of Trust”
Conclusion • All-encompassing solution • Many aspects are implementation-specific • Key to evaluate needs of the applications