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They Who Control Encryption

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If you’ve seen The Imitation Game or studied computer science in school, you have likely heard of Enigma, Alan Turing, or some of the other advances in cryptography that took place during the Second World War. During this time and until the 1970s, governments from around the world had near-total control of all cryptographic systems. …

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HMAC and MACs – The Inner Workings of JWTs

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HMACs and MACs are authentication codes and are often the backbone of JWT authentication systems. A Message Authentication Code (MAC) is a string of bits that depends on a secret key and is sent with a message to prove the message wasn’t tampered with. HMACs are a more strict version of MACs that offer additional …

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(Very) Basic Intro to PGP (GPG)

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PGP, or its open-source alternative, GPG, is a program used to encrypt data such that only an authorized party can decrypt it. In this introduction, we will cover its use-cases and a high-level overview of the algorithms involved. Both programs (and others) adhere to the OpenPGP protocol. Because it is an implementation agnostic protocol, people …

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(Very) Basic Intro to the Scrypt Hash

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Scrypt is a slow-by-design key derivation function designed to create strong cryptographic keys. Simply put, the purpose of the Scrypt hash is to create a fingerprint of its input data but to do it very slowly. A common use-case is to create a strong private key from a password, where the new private key is …

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How SHA-256 Works Step-By-Step

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SHA-2 (Secure Hash Algorithm 2), of which SHA-256 is a part, is one of the most popular hash algorithms around. In this article, we will break down each step of the cryptographic algorithm and work through a real example by hand. SHA-2 is known for its security (it hasn’t broken down like SHA-1) and its …

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Achieving Data Integrity Using Cryptography

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Data integrity refers to the accuracy, legitimacy, and consistency of information in a system. When a message is sent, particularly using an untrusted medium, data integrity provides us confidence that the message wasn’t tampered with. For example, the SSL signature of Qvault provides confidence that the webpage and data coming from our servers are really …

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(Very) Basic Intro To White-Box Cryptography

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White-box cryptography combines methods of encryption and obfuscation to embed secret keys within application code. The goal is to combine code and keys in such a way that the two are indistinguishable to an attacker, and the new “white-box” program can be safely run in an insecure environment. What Does “White-Box” Mean? In penetration testing, …

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JWT Authentication in Golang

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Go is becoming very popular for backend web development, and JWT’s are one of the most popular ways to handle authentication on API requests. In this article, we’ll go over the basics of JWT’s and how to implement a secure authentication strategy in Go! What is a JWT? JSON Web Tokens are an open, industry-standard RFC …

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How Do Brute-Force Attackers Know They Found The Key?

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Brute force attackers guess passwords, passphrases, and private keys in an attempt to eventually get the right answer and crack the security of a system. They systematically guess every combination. For example, if they were guessing telephone numbers in the US: The question is, how do they know when they have the right key? It …

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AES-256 Cipher – Python Cryptography Examples

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Want to encrypt text with a password or private key in Python? AES-256 is a solid symmetric cipher that is commonly used to encrypt data for oneself. In other words, the same person who encrypts the data also decrypts it, the way personal password managers work. Dependencies For this tutorial, we’ll be using Python 3, …

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