About Wentz Wu

Wentz is a co-founder of Amicliens, a company from Taiwan delivering business solutions. He enjoys applying IT technologies to solve business problems and has been working in the IT industry for over 20 years.

Modularization and Encapsulation

Source: visual-paradigm.com

A module is a functional unit that accepts inputs and produces outputs. Modularization is the process of putting things of interest into a module and minimizing dependencies upon external things outside the module. High cohesion and low coupling are well-known modularization principles.

Encapsulation puts things in a module and protects them by controlling the visibility of outsiders. Most object-oriented programming (OOP) languages support encapsulation through the language construct – class, a wrapper of primitive data types (properties) and codes (methods). Members in a class can be seen in public, isolated in private, or protected and shared by child classes only.

WUSON Peacock Guardian Model

This diagram summarizes what I’ve learned these years in the Cybersecurity arena. I hope it helps in practice and the journey of CISSP. It defines assets from the perspective of information systems (the peacock), aligns with the ISC2 control types mentioned in OSG, and incorporates GRC, business mindset, and cultural awareness.

Understanding USB

The article, USB: Port Types and Speeds Compared – Choosing the right USB cable for your computer and peripherals by Tripp Lite by Eaton, provides informative information about USB standards and connectors.

USB 1.1Full Speed USB1998A
12 Mbps3 m
USB 2.0Hi-Speed USB2000 A (Micro, Mini)
B (Micro, Mini)
480 Mbps5 m
USB 3.2 Gen 1 USB 3.0
USB 3.1 Gen 1
2008 (USB 3.0)
2013 (USB 3.1)
B (Micro)
5 Gbps3 m
USB 3.2 Gen 2 USB 3.1
USB 3.1 Gen 2
SuperSpeed 10Gbps
2013 (USB 3.1)A
B (Micro)
10 Gbps3 m
USB 3.2 Gen 2×2 USB 3.2
SuperSpeed 20Gbps
2017 (USB 3.2)C20 Gbps3 m
USB 4 USB4 Gen 2×2
USB4 20Gbps
2019C20 Gbps0.8 m
USB 4 USB4 Gen 3×2
USB4 40Gbps
2019C40 Gbps0.8 m
Source: Tripp Lite by Eaton

A USB Type-C connector has twelve pins. Four pairs of pins, aka “lanes,” are used to transmit (TX) and receive (RX) data, as highlighted in the following diagram by Eaton.

Both USB 3.0 (5 Gbps) and USB 3.1 (10 Gbps) can use the Type-C connector but only one TX lane and one RX lane, depending on the orientation of the connector. USB 3.2 takes advantage of all four lanes to achieve a 20 Gbps data rate.

USB Connectors

Source: TeleTec

USB-C Connector Pin Layout

Source: Texas Instruments
Source: The Customize Windows

USB 3.2 Gen 2 (10Gb) Speed Test: 531 MB out of 10 Gb (1000MB or so)

  • UGREEN M.2 SSD Case with NVMe and USB 3.2 Gen 2 (10 Gb) connectors
  • Transcend M.2 SSD 1TB with NVMe PCIe Gen4 X4 (8 GB)
  • USB 3.2 Gen 2X2 (20Gb) Expansion Card on PCIe Gen 3 X4 (4 GB) – ASM3242 Chip

PCIe Gen 3 X16 Speed Test: 1.68 GB out of 4 GB

  • Transcend M.2 SSD 1TB with NVMe PCIe Gen4 X4 (8 GB)
  • M.2 SSD with NVMe (max: 4 lanes) Expansion Card on PCIe Gen 3 X16 (16 GB)


Linux Notes

Secure Shell

Linux error detection and correction (EDAC)

Trusted Platform Module (TPM)



IPsec Internet Key Exchange (IKE)

Image Source: Meddane

IPsec provides security services through AH and ESP. The two IPsec peers establish security associations for key exchange and security services by the Internet Key Exchange (IKE) protocol. RFC 2409 specifies the Internet Key Exchange Protocol (IKEv1), while RFC 7296 defines the Internet Key Exchange Protocol Version 2 (IKEv2).

Security Associations for Key Exchange

In IKEv1, the ISAKMP SA is two-way or bi-directional:

The ISAKMP SA is bi-directional. That is, once established, either party may initiate Quick Mode, Informational, and New Group Mode Exchanges.

~ RFC 2409

Security Associations for AH and ESP

Both AH and ESP security associations (one-way, either inbound or outbound) are established based on the IKE security association. In IKEv2, SAs established based on IKE SA are called Child SAs.

SA (Security Association): a one-way (inbound or outbound) agreement between two communicating peers that specifies the IPsec protections to be provided to their communications. This includes the specific security protections, cryptographic algorithms, and secret keys to be applied, as well as the specific types of traffic to be protected.

~ RFC 6071

Internet Key Exchange (IKE) Version 1

In IKE v1, ISAKMP defines “phases,” while Oakley defines “modes.” Security association negotiation happens in each mode, e.g., Main Mode, Aggressive Mode, and Quick mode.

In phase 1, a bi-directional secure, authenticated channel, aka ISAKMP security association (SA), is established between the two peers. Either “Main Mode” or “Aggressive Mode” is used in phase 1 to do so.

In phase 2, a one-way security association for AH or ESP is established using the “Quick Mode.”

For a successful and secure communication using IPsec, the Internet Key Exchange (IKE) protocols take part in a two-step negotiation. Main mode or Aggressive mode (within Phase 1 negotiation) authenticate and/or encrypt the peers. Quick mode (Phase 2) negotiates the algorithms and agree on which traffic will be sent across the VPN. Let’s take a further look at Quick mode phase (Phase 2) and what it’s role is within an IPsec VPN tunnel.

~ Internet-Computer-Security.com

IKEv1 Phase 1: Main Mode

Image Source: yurmag

IKEv1 Phase 2: Quick Mode

Image Source: yurmag



Effective CISSP Questions

According to NIST SP 800-30 R1, “assessing risk requires the careful analysis of threat and vulnerability information to determine the extent to which circumstances or events could adversely impact an organization and the likelihood that such circumstances or events will occur.” Which of the following should be determined first before conducting a risk assessment? (Wentz QOTD)
A. Risk assessment methodology
B. Analysis approach
C. Assessment approach
D. Analytic approach

Kindly be reminded that the suggested answer is for your reference only. It doesn’t matter whether you have the right or wrong answer. What really matters is your reasoning process and justifications.

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