In which way does a Secure Socket Layer (SSL) server prevent a “man-in-the-middle” attack?
A.
It uses signed certificates to authenticate the server’s public key.
B.
A 128 bit value is used during the handshake protocol that is unique to the connection.
C.
It uses only 40 bits of secret key within a 128 bit key length.
D.
Every message sent by the SSL includes a sequence number within the message contents.
Explanation:
Secure Sockets Layer (SSL). An encryption technology that is used to provide secure transactions
such as the exchange of credit card numbers. SSL is a socket layer security protocol and is a twolayered protocol that contains the SSL Record Protocol and the SSL Handshake Protocol. Similiar to
SSH, SSL uses symmetric encryption for private connections and asymmetric or public key
cryptography (certificates) for peer authentication. It also uses a Message Authentication Code for
message integrity checking. Krutz: The CISSP Prep Guide pg. 89. It prevents a man in the middle
attack by confirming that you are authenticating with the server desired prior entering your user
name and password. If the server was not authenticated, a man-in-the-middle could retrieve the
username and password then use it to login. The SSL protocol has been known to be vulnerable to
some man-in-the-middle attacks. The attacker injects herself right at the beginning of the
authentication phase so that she obtains both parties’ keys. This enables her to decrypt and view
messages that were not intended for her. Using digital signatures during the session-key exchange
can circumvent the man-in-the-middle attack. If using kerberos, when Lance and Tanya obtain each
other’s public keys from the KDC, the public keys are signed by the KDC. Because Tanya and Lanace
have the public key of the KDC, they both can decrypt and verify the signature on each other’s public
key and be sure that it came from the KDC itself. Because David does not have the private key of the
KDC, he cannot substitute his pubic key during this type of transmission. Shon Harris All-In-One CISSP
Certification pg. 579. One of the most important pieces a PKI is its public key certificate. A certificate
is the mechanism used to associate a public key with a collection of components sufficient to
uniquely authenticate the claimed owner. Shon Harris All-In-One CISSP Certification pg. 540.