Is Open-Source Cryptography Really Secure?

By Lane Wagner – @wagslane on Twitter

The purpose of cryptography is to keep information private, and the purpose of open-source is to make code public…

…Danger!

Just kidding.

I’ve been asked this several times by multiple people so I figured it is a subject worth addressing. Many developers seem to be under the impression that crypto and security systems (the application-specific implementation of cryptosystems) are more secure if their details are kept private.

This can’t be further from the truth

According to Kerckhoffs’s principle, also known as Shannon’s maxim:

The enemy knows the system. One ought to design systems under the assumption that the enemy will immediately gain full familiarity with them. #security #opensource #privacy
Click To Tweet

There are several reasons as to why this is a good rule to live by, let’s examine each one.

1. Obfuscation Isn’t Encryption

If a developer is operating under the assumption that attackers won’t know about the details of their code, they may be tempted to try to build in security that is dependent on that.

For example, they may encode data in a confusing way instead of encrypting it, assuming that the enemy will think it is encrypted, or not be able to guess HOW it was encoded.

BAD.

When something needs to be kept secret, always encrypt.

2. You Probably Suck

If you roll your own crypto, you are likely to overlook vulnerabilities that have been accounted for in open-source versions. By the way, I don’t mean that you specifically suck at writing crypto, I mean that no one person (or organization) can reasonably be responsible for vetting all possible attack vectors. Open-source allows the worldwide developer community to help expose problems with the code.

Not only are you likely to have problems in underlying mathematics and algorithms, but it is likely that your application-level implementation will also have vulnerabilities. There are no industry standard best practices to follow for your custom algorithms.

3. Get New Updates

By using popular crypto libraries that are regularly updated, your code won’t be vulnerable to the recently discovered attacks on the algorithms you are using.

Take advantage of the community, and give back by contributing when you can!

Golang: https://golang.org/pkg/crypto/

Node: https://nodejs.org/api/crypto.html

Python: https://pypi.org/project/cryptography/

Thanks For Reading

Lane on Twitter: @wagslane

Lane on Dev.to: wagslane

Download Qvault: https://qvault.io

The post Is Open-Source Cryptography Really Secure? appeared first on Qvault.



source https://qvault.io/2020/01/30/is-open-source-cryptography-really-secure/?utm_source=rss&utm_medium=rss&utm_campaign=is-open-source-cryptography-really-secure

Comments

Post a Comment

Popular posts from this blog

Why is Exclusive Or (XOR) Important in Cryptography?

Image
If you are getting into cryptography, or just trying to understand the fundamentals, you may have noticed that the exclusive-or operation is used quite often, especially in ciphers. What is XOR ( ⊕ )? XOR, or “exclusive or” operates on binary data. It returns true if both of its inputs are opposites (one false and one true), otherwise, it returns false. An example in go code would be something like: func exclusiveOr(a bool, b bool) bool { return a != b } XOR Cipher – The Perfect Cipher The XOR operation can be used as a simple cipher for encrypting and decrypting messages with a single key. This is known as symmetric encryption. It is interesting to note that if: The key is the same size as the message The key is kept secret and generated truly randomly Then the cipher is impossible to crack. This is known as a one time pad . However, a simple XOR shouldn’t be used in production due to the key length needing to be too long to be practical. Cipher Example A...
Read more

Base64 vs Base58 Encoding

Image
By Lane Wagner –  @wagslane  on Twitter Base64 is one of the most popular encoding formats for representing data. Have some binary data? Base64 encode it for convenient readability and parsing. Base58 is just another encoding format (with 58 characters instead of 64, and has gained popularity largely due to Bitcoin and other cryptocurrencies. When it comes to data encoding, there is typically a trade-off made between: Human Readability: Do humans have a good idea of what is being represented at a glance? Efficient data compression: How many bytes are used to represent the same data? Let’s rank Base58, Base64, and ASCII encoding against each other using these metrics! First: A Note on Binary All data is stored in a raw binary format on computers. These encoding formats (Base64, Base58, and ASCII) are just different ways of reading and writing binary data. For example, in Base64 the binary code 000000 represents the letter A , but in ASCII the binary 00000000 repres...
Read more

(Very) Basic Intro to Hash Functions (SHA-256, MD-5, etc)

Image
This is going to be a basic introduction to hash functions. I will assume most of my audience is here to gain an understanding of why hash functions are used and the basic idea of why they work. My goal is to explain it in a general sense, I will be omitting proofs and implementation details and instead focusing on the high-level principles. Why Use A Hash Function? Hash functions are used all over the internet in order to securely store passwords, find duplicate records, quickly store and retrieve data, and more. For example,  Qvault  uses hashes to extend master passwords into private encryption keys. A longer list of uses here:  https://en.wikipedia.org/wiki/Hash_function#Uses I want to focus on several important features of hash functions, arguably the most important features. Hash functions scramble data deterministically No matter the input, the output of a hash function always has the same size The original data can not be retrieved from the scrambled d...
Read more