computer science

NSA Suite B Cryptography

NSA Suite B Cryptography is a computer 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 NSA Suite B Cryptography rather than just read about it. In short: NSA Suite B Cryptography was a set of cryptographic algorithms promulgated by the National Security Agency as part of its Cryptographic Modernization Program. It was to serve as an interoperable cryptographic base for both unclassified information and most classified information.

Key takeaways

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

Reference excerpt

NSA Suite B Cryptography was a set of cryptographic algorithms promulgated by the National Security Agency as part of its Cryptographic Modernization Program. It was to serve as an interoperable cryptographic base for both unclassified information and most classified information. Suite B was announced on 16 February 2005. A corresponding set of unpublished algorithms, Suite A, is "used in applications where Suite B may not be appropriate. Both Suite A and Suite B can be used to protect foreign releasable information, US-Only information, and Sensitive Compartmented Information (SCI)."

In addition, "[d]uring the transition to the use of elliptic curve cryptography in ECDH and ECDSA, DH, DSA and RSA can be used with a 2048-bit modulus to protect classified information up to the SECRET level." In 2015, NSA replaced Suite B with the Commercial National Security Algorithm Suite (CNSA). The general selection of algorithms types remain unchanged. DSA was removed. DH and RSA were reclassified as "supported" instead of "legacy" with the minimum modulus size raised to 3072 bits. In 2018, the Suite B IETF RFC documents were reclassified as historical.

History In December 2006, NSA submitted an Internet Draft on implementing Suite B as part of IPsec. This draft had been accepted for publication by IETF as RFC 4869, later made obsolete by RFC 6379. Certicom Corporation of Ontario, Canada, which was purchased by BlackBerry Limited in 2009, holds some elliptic curve patents, which have been licensed by NSA for United States government use. These include patents on ECMQV, but ECMQV has been dropped from Suite B. AES and SHA had been previously released and have no patent restrictions. See also RFC 6090. As of October 2012, CNSSP-15 stated that the 256-bit elliptic curve (specified in FIPS 186-2), SHA-256, and AES with 128-bit keys are sufficient for protecting classified information up to the Secret level, while the 384-bit elliptic curve (specified in FIPS 186-2), SHA-384, and AES with 256-bit keys are necessary for the protection of Top Secret information. However, as of August 2015, NSA indicated that only the Top Secret algorithm strengths should be used to protect all levels of classified information. In 2018 NSA withdrew Suite B in favor of the CNSA.

Implementation requirements Using an algorithm suitable to encrypt information is not necessarily sufficient to properly protect information. If the algorithm is not executed within a secure device the encryption keys are vulnerable to disclosure. For this reason, the US federal government requires not only the use of NIST-validated encryption algorithms, but also that they be executed in a validated Hardware Security Module (HSM) that provides physical protection of the keys and, depending on the validation level, countermeasures against electronic attacks such as differential power analysis and other side-channel attacks. For example, using AES-256 within an FIPS 140-2 validated module is sufficient to encrypt only US Government sensitive, unclassified data. This same notion applies to the other algorithms.

Successors

Quantum resistant suite In August 2015, NSA announced that it is planning to transition "in the not too distant future" to a new cipher suite that is resistant to quantum attacks. "Unfortunately, the growth of elliptic curve use has bumped up against the fact of continued progress in the research on quantum computing, necessitating a re-evaluation of our cryptographic strategy." NSA advised: "For those partners and vendors that have not yet made the transition to Suite B algorithms, we recommend not making a significant expenditure to do so at this point but instead to prepare for the upcoming quantum resistant algorithm transition." New standards are estimated to be published around 2024.

Commercial National Security Algorithm Suite

The Suite B algorithms have been replaced by Commercial National Security Algorithm (CNSA) Suite algorithms in 2015.

Worked examples

Example 1 — a first encounter with NSA Suite B Cryptography

Start with the simplest possible case. Write down what NSA Suite B Cryptography claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In computer 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 NSA Suite B Cryptography 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 NSA Suite B Cryptography 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 NSA Suite B Cryptography

In research: NSA Suite B Cryptography appears in computer 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 NSA Suite B Cryptography 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: NSA Suite B Cryptography is common in secondary-school and first-year university syllabi. It links to neighbouring topics Cryptography standards, National Security Agency cryptography, Standards of the United States, so understanding it makes those chapters shorter.
In everyday life: Look for NSA Suite B Cryptography 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 NSA Suite B Cryptography in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what NSA Suite B Cryptography 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 NSA Suite B Cryptography out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is NSA Suite B Cryptography in simple terms?

Why does NSA Suite B Cryptography matter?

Because it connects several computer 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 NSA Suite B Cryptography?

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 NSA Suite B Cryptography.