Bitcoin Script Minimal Push Encoding Rules Explained
Bitcoin's script interpreter rejects non-minimal push opcodes silently. The exact rule, the malleability problem it solves, and where developers go wrong.
№ 014BitcoinBitcoin AssumeValid and IBD Security Explained
AssumeValid skips signature checks during Bitcoin's initial sync, the mechanics, the real risks, and what malicious peers can and cannot do.
№ 015BitcoinBitcoin's Median Time Past Rule Explained
Miners set their own block timestamps. Bitcoin's Median Time Past rule is why that doesn't let them unlock CLTV-protected coins early, the mechanic, precisely.
№ 016EthereumEthereum Validator Penalties: Inactivity Leaks vs Slashing
Inactivity leaks and slashing penalize Ethereum validators through different mechanisms. The math, timelines, and what each means for staking economics.
№ 017BitcoinBitcoin Script Clean Stack Rules in Tapscript
How Bitcoin's clean stack rule works after Tapscript execution, why it differs from legacy Script, and what it means for spending conditions.
№ 018EthereumEthereum Withdrawal Credentials: BLS to Execution Migration
How Ethereum validators migrate withdrawal credentials from BLS to execution-layer addresses, what the process does mechanically, and why it's a one-way door.
№ 019EthereumEthereum Blob Pruning and the Fraud Proof Timing Risk
Ethereum deletes blob data after ~18 days, a pruning schedule that creates a concrete asymmetry for anyone challenging a rollup fraud proof.
№ 020SecurityBitcoin xpub Exposure: One Leaked Key, Whole Wallet at Risk
A leaked Bitcoin extended public key exposes every address in your wallet tree, past and future. The mechanism, the math, and the containment steps.
№ 021BitcoinBitcoin Sighash Flags: What Signatures Actually Commit To
Bitcoin sighash flags control exactly which transaction fields a signature binds to, understanding them separates safe wallet code from exploitable wallet code.
№ 022BitcoinBitcoin's assumevalid: Script Skipping Explained
Bitcoin Core's assumevalid parameter cuts initial sync from days to hours by skipping old script checks, while still verifying proof-of-work and every UTXO.
№ 023BitcoinBitcoin Covenant Opcodes: Trust Assumptions Compared
OP_CTV, OP_VAULT, and CSFS enforce spending rules differently. Their trust assumptions diverge sharply, and that gap determines your real attack surface.
№ 024BitcoinBitcoin's Quadratic Hashing Bug: SegWit's Fix Explained
Bitcoin's sighash algorithm scaled as N² with input count, creating a live attack vector. The mechanics, the 2015 megatransaction, and how BIP143 closed it.