Chapter 2 — Computing systems | Bachelor's Systems, endpoints and hardware security

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Chapter 2 — Computing systems

Lesson map

Lesson 02 published. Map, example, EX004.

flowchart TD
  N0["Learning outcomes"]
  N1["2.1 Laptops and servers"]
  N2["2.2 Storage"]
  N3["2.3 Firmware and the TPM"]
  N4["2.4 Memory"]
  N5["2.5 Inventory of hardware"]
  N6["Servers in the case"]
  N7["Synthesis"]
  N0 --> N1 --> N2 --> N3 --> N4 --> N5 --> N6 --> N7
  N7 --> EX["Worked example"]
  EX --> Q["Exercise EX004"]

Logical drawing

flowchart LR
  N0["Learning outcomes"]
  N1["2.1 Laptops and servers"]
  N2["2.2 Storage"]
  N3["2.3 Firmware and the TPM"]
  N4["2.4 Memory"]
  N5["2.5 Inventory of hardware"]
  N6["Servers in the case"]
  N7["Synthesis"]
  N0 --> N1 --> N2 --> N3 --> N4 --> N5 --> N6 --> N7 --> Q["EX004"]

[Learning outcomes]
    |
    v
[2.1 Laptops and servers]
    |
    v
[2.2 Storage]
    |
    v
[2.3 Firmware and the TPM]
    |
    v
[2.4 Memory]
    |
    v
[2.5 Inventory of hardware]
    |
    v
[Servers in the case]
    |
    v
[Synthesis]
    |
    v
[Worked example] --> [Exercise EX004]

Learning outcomes

You will (1) describe the parts of laptops and servers; (2) explain storage, memory and firmware; (3) relate hardware to data exposure.

2.1 Laptops and servers

A laptop and a server share the same building blocks: processor, memory, storage, firmware and network interfaces. Servers run continuously and provide shared services such as file storage; laptops travel and are used by one person. Travel makes laptops easier to lose.

At Bramley the difference shows up in daily practice and in the risks Aisha records. The four servers stay in the office cupboard and run all day, while the 45 laptops move between the office, staff homes and cars. Aisha records each device's role as laptop or server in her inventory, because later controls, such as patch windows and encryption, are planned differently for each group.

2.2 Storage

Laptop storage keeps data when powered off. Without encryption, anyone who removes the disk or boots another system can read it. This is exactly what made the stolen Bramley laptop a reportable incident.

Aisha checks how the stolen laptop's disk was set up from Gareth's purchase notes. It used a standard internal drive with encryption switched off, the factory default for that model. Anyone with a cable or a second computer could have copied the tenant files in minutes, without knowing a single password. That is why storage, not the login screen, is the first hardware topic in her project.

2.3 Firmware and the TPM

Firmware starts the machine; a Trusted Platform Module stores keys and can release the disk encryption key only when the expected boot components load. Microsoft's BitLocker documentation describes this approach for Windows laptops.

For Bramley the TPM matters because it lets encryption work without asking staff for an extra password each morning. If someone moves the disk into another computer, the TPM in the original laptop is not there to release the key, so the data stay unreadable. Aisha notes which laptop models have a TPM and which firmware version each runs, because both affect the rollout later in the course.

2.4 Memory

Memory holds working data and is cleared when power is lost. Locking or shutting down laptops when unattended reduces the time data sits in an unlocked session.

Aisha connects this to the stolen laptop, which was taken from a car and may have been asleep rather than shut down. A laptop that is only asleep keeps its session in memory, so Bramley's guidance will ask staff to shut down or hibernate laptops before travelling. Gareth adds a screen-lock timeout to the baseline list, so an unattended session locks itself even when staff forget.

2.5 Inventory of hardware

Aisha records each device's model, age and whether it has a TPM. Two older laptops lack one, which affects how they can be encrypted.

The two laptops without a TPM are the oldest in the fleet, and Aisha flags them for a different encryption approach and early replacement. Her inventory has one row per device, with columns for asset tag, model, purchase year, TPM present and firmware version. Gareth fills the gaps from purchase records, and the finished table becomes the starting point for the asset register used in later chapters.

Servers in the case

Bramley's four servers hold the shared files, the finance system, the directory that controls logons and an old housing application. They sit in a small cupboard in the office. Because they hold more data than any laptop, their protection matters, but their risks differ: they rarely move, so theft is less likely, while unneeded services and missed updates matter more.

Worked example

Gareth asks whether a password on the laptop would have been enough. Aisha explains that a login password stops someone using Windows, but not someone reading the disk directly; only encryption protects the data at rest.

Synthetic case. Synthetic.

Errors and limits

Hardware features help only when enabled; many laptops ship with encryption off.

Exercises

EX004 — Travel risk. Why are laptops more exposed than servers? Rubric: 3 = they travel and are lost; 2 = partial; 1 = vague; 0 = none.
EX005 — Login password. Why is a login password not enough? Rubric: 3 = disk readable directly; 2 = partial; 1 = vague; 0 = none.
EX006 — TPM role. What does the TPM do for encryption? Rubric: 3 = releases key for expected boot; 2 = partial; 1 = vague; 0 = none.

Synthesis

Data at rest on portable hardware needs encryption.

Continue studying — chapter 02 of 40

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