Network Security Subcategories

Networking Overview I	Network Hardware
Freshers	Socket Secure Layer I
Network Security	Classful Addressing
Experienced	Secure Shell I
Designing Subnets I

Which is the correct order of the SSH Transport Layer Protocol Packet Exchanges?

A. Algorithm negotiation; end of key exchange; service request; identification string exchange
B. Identification string exchange; algorithm negotiation; end of key exchange; service request
C. Identification string exchange; end of key exchange; service request; algorithm negotiation
D. Algorithm negotiation; identification string exchange; end of key exchange; service request

Explanation: The correct order is: Identification string exchange; Algorithm Negotiation; End of key exchange; Service request.

How many trust models does the RFC 4251 dictate?

A. 2
B. 3
C. 4
D. 5

Explanation: The RFC 4251 dictates two alternative trust models : The local database model and the certification authority model.

The correct order of operations in the SSH Transport Layer Protocol Packet Formation is –

A. Compression; encryption; padding and addition of seq bits
B. Compression; padding and addition of seq bits; encryption
C. Encryption; padding and addition of seq bits; compression
D. Padding and addition of seq bits; encryption; compression

Explanation: The correct order of operation is – Compression; Padding and Addition of seq bits; Encryption.

Size of the sequence number is-

A. 32 bits
B. 48 bits
C. 56 bits
D. 64 bits

Explanation: The seq# is 32 bits.

Which one of the following does not undergo the encryption procedure?

A. Pdl
B. Pktl
C. Seq#
D. Padding

Explanation: The seq# 32 bits does not undergo encryption.

What is the recommended cryptographic algorithm for the Secure Shell Transport Layer?

A. Twofish 128
B. Aes 192
C. Aes 128
D. Blowfish

Explanation: aes 128 is the reccomended cryptographic algorithm.

What is the recommended modes of operation for encryption and decryption in the Secure Shell Transport Layer?

A. Ecb
B. Ofb
C. Cbc
D. Cfb

Explanation: The cipher block chaining mode is the recommended mode of operation in the SSH Transport layer.

What is the recommended MAC algorithm for the SSH Transport Layer?

A. Hmac €? md5
B. Hmac €? md5 €? 96
C. Hmac sha1 €? 96
D. Hmac sha1

Explanation: The recommended MAC algorithm for the SSH Transport Layer is the HMAC SHA1 – 96.

The session Identifier remains constant throughout the SSH connection.

A. True
B. False
C.
D.

Explanation: The hash value H servers as a session identifier for this connection. Once computed, the session identifier is not changed, even if the key exchange is performed again for this connection to obtain fresh keys.

In the Key generation procedure, the Initialization Vector from the server to client is represented as:

A. Hash(k||h||€?c”||session_id)
B. Hash(k||h||€?b”||session_id)
C. Hash(k||h||€?f”||session_id)
D. .

Explanation: The Initialization Vector from the server to client is given by HASH(K||H||”B”||session_id).