Just Cryptography

Learn Cryptography and Information Security

Category: Data integrity

• What is Galois/Counter Mode (GCM)?

The Galois/Counter Mode (GCM) is an algorithm for authenticated encryption that addresses confidentiality and authenticity at the same time. It is a NIST standard designed to avoid security flaws in authenticated encryption. GCM algorithm  Find below a graphical representation of the GCM algorithm. This representation is based on the NIST recommendation. You can find the…

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• What is Authenticated Encryption (AE)?

Authenticated Encryption (AE) is an encryption approach that addresses confidentiality and authenticity at the same time. Find below a summary of 4 approaches that aims to provide confidentiality and integrity at the same time. Approach Description Example of applications Encrypt, then authenticate – Generate two keys – Encrypt the message with the first key –…

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• What is a Digital Signature and how does it work?

A digital signature is a mechanism we can use to verify the authenticity of a message/document. It is usually needed in situations when there is no trust between sender and receiver. We can use a digital signature to verify the author of the signature, to authenticate the content of the message. Also, third parties must…

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• What is a Cryptographic Hash Function?

A cryptographic hash function is an algorithm that has two main properties: it is a one-way function and is collision-free. As per function definition, it transforms one input into only one output. By one way function we mean that is computationally infeasible to find the input related to a given output. The best attack known…

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• Cryptographic hash functions and HMAC

Hash functions have several applications in cryptography. In this article, you will learn the characteristics of hash functions and some of their applications. Also, I’ll describe some of the hash functions that are already being used. Lastly, you will learn about HMAC and an example of implementation. Hash functions A hash function is a one-way…

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