A
• Phase _?_ depends on public-key encryption used. The server passes a certificate to the client, optionally a request for a certificate from the client.
• Server’s certificate is highlighted as optional as the connection may only need a DH key exchange, without certificates, or use a previously shared secret key. However, these options are not used in practice. The server’s certificate is almost always exchanged
in this phase.
• server_ done message, which indicates the end of the server hello messages.
What is Phase 2
• Enveloped data
- Encrypted content and associated keys
• Signed data
- Base-64 encoded (message + signed digest)
• Clear-signed data
- Cleartext message + Base-64 encoded (signed digest)
• Signed and enveloped data
• Signed and encrypted data.
What are the Four main functions of S/MIME
Heartbleed exploit attacks this TLS protocol
What is the Heartbeat Protocol
• Binary-to-text encoding schemes that represent binary data in sequences of 24 bits that can be represented by blocks of four 6-bit Base64 digits.
• Designed to carry binary data across channels that only support text content.
what is Base64 Encoding
• Authentication
• Message integrity
• Non-repudiation of origin (using digital signatures)
• Privacy
• Data security (using encryption)
Features of S/MIME
• Used to conveys TLS-related alerts to peer entity
• Messages are compressed and encrypted, as specified by the current state
• Each message consists of two bytes:
• First byte: takes the value warning(1) or fatal(2) to convey the severity of the message
• If the level is fatal, TLS immediately terminates the connection
• Other connections on the same session may continue, but no new connections on this session may be established
• Second byte: contains a code that indicates the specific alert, e.g., close_notify to notify the recipient that the sender won’t send any more messages on this connection.
Alert Protocol
• When ________ is used, the following elements of the communication are encrypted:
• Full URL of a requested document (not the Server Name to resolve the DNS).
• Contents of the document
• Contents of browser forms (filled in by browser user)
• Cookies sent from browser to server and from server to browser
• Contents of HTTP header
HTTPS
Phase _?_ Client verifies the certificate. If valid, the client sends messages back to the server, depending on the underlying public-key scheme.
What is Phase 3
Specification of cryptographically signing e-mail messages permitting a signing
domain to claim responsibility for a message in the mail stream
• Enables managing security at the domain level, not the user level.
• Has been widely adopted by almost all e-mail providers
What is DomainKeys Identified Mail (DKIM)
• The lower layer of TLS
• Services every other protocol in the upper layer
• Provides: Message Confidentiality, Message Integrity
What is The Record Protocol