Helping Hand Questions for 312-50v13

This falls under Requirement 8 of PCI DSS: "Identify and authenticate access to system components," which supports the objective of implementing strong access control measures.

CEH v13 Reference:

Module 20: Hacking Mobile Platforms and IoT – Compliance Standards

"PCI DSS requires unique identification for each person with access to ensure accountability and access control."

Triple DES is another mode of DES operation. It takes three 64-bit keys, for an overall key length of 192 bits. In Stealth, you merely type within the entire 192-bit (24 character) key instead of entering each of the three keys individually. The Triple DES DLL then breaks the user-provided key into three subkeys, padding the keys if necessary in order that they are each 64 bits long. The procedure for encryption is strictly an equivalent as regular DES, but it’s repeated 3 times , hence the name Triple DES. the info is encrypted with the primary key, decrypted with the second key, and eventually encrypted again with the third key.

Triple DES runs 3 times slower than DES, but is far safer if used properly. The procedure for decrypting something is that the same because the procedure for encryption, except it’s executed in reverse. Like DES, data is encrypted and decrypted in 64-bit chunks. Although the input key for DES is 64 bits long, the particular key employed by DES is merely 56 bits long . the smallest amount significant (right-most) bit in each byte may be a parity , and will be set in order that there are always an odd number of 1s in every byte. These parity bits are ignored, so only the seven most vital bits of every byte are used, leading to a key length of 56 bits. this suggests that the effective key strength for Triple DES is really 168 bits because each of the three keys contains 8 parity bits that aren’t used during the encryption process.

Triple DES Modes

Triple ECB (Electronic Code Book)

• This variant of Triple DES works precisely the same way because the ECB mode of DES.

• this is often the foremost commonly used mode of operation.

Triple CBC (Cipher Block Chaining)

• This method is extremely almost like the quality DES CBC mode.

• like Triple ECB, the effective key length is 168 bits and keys are utilized in an equivalent manner, as described above, but the chaining features of CBC mode also are employed.

• the primary 64-bit key acts because the Initialization Vector to DES.

• Triple ECB is then executed for one 64-bit block of plaintext.

• The resulting ciphertext is then XORed with subsequent plaintext block to be encrypted, and therefore the procedure is repeated.

• This method adds an additional layer of security to Triple DES and is therefore safer than Triple ECB, although it’s not used as widely as Triple ECB.

The recommended architecture for secure web application deployment is a multi-tiered setup:

Web server in the DMZ (public-facing)

Application server on the internal network

Database server on the internal network

This design limits the exposure of critical components. Only the web server is exposed to the internet, while application and database servers are shielded by firewalls and only accessible internally.

Reference – CEH v13 Official Study Guide:

Module 10: Hacking Web Servers

Quote:

“Place the web server in the DMZ and keep the application and database servers within the internal network. This reduces the attack surface and provides layered security.”

Incorrect Options Explained:

A. Internal placement makes them inaccessible externally.

C & D. Exposing the database or all servers to the internet introduces significant risk.

=

A Network-based Intrusion Detection System (NIDS) monitors all network traffic for signs of suspicious activity across multiple hosts. In large environments with critical assets (e.g., financial or healthcare networks), NIDS is ideal because it provides visibility into entire network segments, not just individual systems.

NIDS can be deployed at strategic points (e.g., DMZs, VLANs, subnets) to detect unauthorized access, malware activity, or policy violations.

Reference – CEH v13 Official Courseware:

Module 13: Evading IDS, Firewalls, and Honeypots

Quote:

“Network-based IDS monitors traffic across an entire subnet or segment and is most effective in large environments to detect malicious activity before it reaches critical assets.”

Incorrect Options Explained:

A. Honeypots attract and log attacker behavior, but do not provide network-wide detection.

B. Firewalls filter traffic but are not detection systems.

D. HIDS monitors activity on a single host only.

=