

How Bitcoin Actually Works: A First Principles Guide
From entropy and SHA-256 to proof of work and the 21 million cap: a first principles guide to how Bitcoin works, and what you can verify yourself.
In this article
As Co-founder and CTO of Swan Bitcoin, I focus relentlessly on security, ensuring that we deploy extensive attention, budget, and engineering resources to protect our systems and client assets. This commitment is the foundation of the industry-leading protection provided by our suite of security enhancements, known as Swan Guard.
The core technology behind real Bitcoin relies on cryptographic proof instead of trust. This philosophy dictates that money should be secured in a way that is physically impossible for others to access. Yet, when accessing digital financial services, many clients must still rely on traditional login methods that are prone to compromise. We previously identified passkeys as an important new security feature to implement.
Today, we are proud to announce that Passkeys are now available for all Swan clients, delivering significantly faster and more secure logins with device-based authentication.
This technology uses device hardware features, cryptography, and device verification using your face or fingerprint to verify your identity. Passkeys eliminate the vulnerabilities inherent in standard passwords and drastically minimizes the attack surface for social engineering. Just as Bitcoin decouples financial transactions from real-world identities and centralized repositories of consumer data, passkeys move away from reliance on centralized password storage.
Passkeys are a crucial new layer of security, making access to your funds both easier and more secure, aligning with our commitment to utilizing industry-leading technology in our operations. Swan is constantly building new security features to enhance Swan Guard. We strongly encourage all clients to adopt Passkeys.
Yan Pritzker is the cofounder and CTO of Swan Bitcoin and the author of Inventing Bitcoin.
Thoughts on Bitcoin from the Swan team and friends.
From entropy and SHA-256 to proof of work and the 21 million cap: a first principles guide to how Bitcoin works, and what you can verify yourself.
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