science

Secure Terminal Equipment

Secure Terminal Equipment is a science topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Secure Terminal Equipment rather than just read about it. In short: Secure Terminal Equipment (STE) is the U.S. government's current (as of 2008) encrypted telephone communications system for wired or "landline" communications. STE is designed to use ISDN telephone lines which offer higher speeds of up to 128 kbit/s and are all digital.

Key takeaways

Secure Terminal Equipment belongs to science; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Secure Terminal Equipment to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Secure Terminal Equipment from memory before moving on to harder problems.

Reference excerpt

Secure Terminal Equipment (STE) is the U.S. government's current (as of 2008) encrypted telephone communications system for wired or "landline" communications. STE is designed to use ISDN telephone lines which offer higher speeds of up to 128 kbit/s and are all digital. The greater bandwidth allows higher quality voice and can also be utilized for data and fax transmission through a built-in RS-232 port. STE is intended to replace the older STU-III office system and the KY-68 tactical system. STE sets are backwards compatible with STU-III phones, but not with KY-68 sets. STE sets look like ordinary high-end office desk telephones and can place unsecured calls to anywhere on the public switched telephone network (PSTN), as well as secured calls on it via the phone's backwards compatible STU-III mode. There is a PC Card slot in the STE that allows a Fortezza Plus (KOV-14) Crypto Card or KSV-21 Enhanced Crypto Card to be inserted. When an NSA-configured Crypto Card is present, secure calls can be placed to other STE phones. STE phones are "releasable" (unlike STU-III sets). All cryptographic algorithms are in the crypto card. Newer STE sets can communicate with systems that use the Secure Communications Interoperability Protocol (SCIP) (formerly Future Narrowband Digital Terminal (FNBDT)). There are upgrade kits available for older units.

Models Office: The Office STE is the most widely used STE and provides voice and data access to ISDN (Integrated Services Digital Network) and PSTN (Public Switched Telephone Network) telecommunications systems. Tactical: The Tactical STE is similar to the Office STE but can also access the TRI-TAC (TRI Service TACtical) network and has a serial EIA-530A/EIA-232 BDI (Black Digital Interface) port. Data: The Data STE provides remote access for voice, fax, data and video-conferencing. This model has two serial EIA-530A/EIA-232 BDI ports and allows for data transfers to multiple destinations. C2: The C2 STE is similar to the Tactical STE but C2 has modified software for use with its Tactical Terminal Locking Handset mechanism. STE-R: Similar to the Data STE, the STE-Remote provides dial-in access to the Defense Red Switch Network (DRSN). VoIP: The STE now has Voice over Internet Protocol (VoIP) capability, available as an upgrade to the current models, or built into some new models. As of 2007, a typical STE terminal cost about $3,100, not including the crypto card.

References

External links The NAVY INFOSEC WebSite on STU-III and STE Archived 2010-12-09 at the Wayback Machine

Illustrations

Secure Terminal Equipment: STE desk set. Note slot in front for Crypto PC Card. — STE desk set. Note slot in front for Crypto PC Card.

Worked examples

Example 1 — a first encounter with Secure Terminal Equipment

Start with the simplest possible case. Write down what Secure Terminal Equipment claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In science, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Secure Terminal Equipment before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Secure Terminal Equipment ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Secure Terminal Equipment

In research: Secure Terminal Equipment appears in science research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses Secure Terminal Equipment in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: Secure Terminal Equipment is common in secondary-school and first-year university syllabi. It links to neighbouring topics Encryption devices, Secure communication, so understanding it makes those chapters shorter.
In everyday life: Look for Secure Terminal Equipment outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

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How to study Secure Terminal Equipment in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Secure Terminal Equipment means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain Secure Terminal Equipment out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Secure Terminal Equipment in simple terms?

Why does Secure Terminal Equipment matter?

Because it connects several science ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Secure Terminal Equipment?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Secure Terminal Equipment.