A passkey is a login credential made of a cryptographic key pair instead of a shared secret. You unlock it with whatever unlocks your phone or laptop (a fingerprint, your face, a PIN), and the website never receives anything it could leak or that you could be tricked into typing somewhere else. Passkeys are the consumer name for FIDO2 credentials, and Apple, Google and Microsoft have supported them since 2022. They fix the two biggest problems with passwords, phishing and reuse, almost completely.

Post-quantum cryptography (PQC) is the set of public-key algorithms built to survive an attack by a large quantum computer. It runs on ordinary computers and ordinary chips. Nothing about it is quantum except the threat it is designed against. The reason anyone outside a cryptography department should care is simple: almost every secure connection you make today, from a bank login to a software update, depends on RSA or elliptic-curve cryptography (ECC), and both fall apart once a big enough quantum machine exists.

A book cipher uses an ordinary published text as the shared secret. Sender and receiver own the same edition, and the encoded message is nothing more than a set of pointers into it. The appeal is obvious. No suspicious key material, no cipher machine, nothing incriminating on a shelf that also holds forty other books. For roughly four centuries this was one of the better options available to spies, conspirators and diplomats working without institutional support.

I don’t have much sympathy for prosecutors who treat a phone’s security feature as evidence of criminal intent. That instinct made this story easy to write off as one more overreach the moment I read the headline. It’s not that simple, and pretending it is would waste the more interesting story sitting right next to it. The DOJ is prosecuting a Cop City protester for allegedly giving CBP a duress passcode — the GrapheneOS feature that wipes a phone’s contents when entered under compulsion — treating the wipe itself as obstruction.

Blockchain API Tutorial: Architectures, Verification, Smart Contracts, and Distributed Systems Blockchain APIs are often introduced as simple interfaces for querying balances, sending transactions, or interacting with smart contracts. That framing is technically correct, but it misses the deeper reality. A blockchain API is not merely a gateway into a database — it is an interface into a distributed consensus system operating under adversarial conditions. Traditional APIs expose mutable centralized state controlled by a single authority.

Google researchers have published findings that tighten the timeline on one of the most consequential threat scenarios in digital finance: a quantum computer capable of breaking the cryptographic foundations of Bitcoin and other blockchain-based assets. The specific target is elliptic-curve cryptography — and more precisely, the elliptic curve discrete logarithm problem for 256-bit curves (ECDLP-256), which underlies the key pairs that secure Bitcoin wallets and transactions. The researchers’ updated estimates reduce the quantum computing hardware requirements needed to execute such an attack, meaning the capability threshold is lower than the field previously assumed.

Quantum computing tends to get introduced as a faster computer, but that framing misses what actually makes it different. It’s not just speed—it’s a different way of representing and manipulating information. Classical computers rely on bits that are either zero or one, clean and definite. Quantum systems use qubits, which can exist in combinations of states at once, a property tied to superposition. That alone sounds abstract, maybe even a bit hand-wavy at first, but the consequences are very real.