# kaal:claim:3125827-015

**Claim.** The long range attack is a fundamental problem every proof of stake protocol must address: because no energetic outlay is required to build blocks, a malicious producer can fabricate a long chain forked from an earlier valid block, and a newly joining node lacking proof of work hashes cannot objectively tell which chain is genuine.

**Type.** failure  **Support.** argued

**Holds when.**

- new nodes joining without a trusted checkpoint
- PoS chains with no energy cost to block creation

**Source quote.**

> The long-range attack is a fundamental problem PoS protocols must address, where a malicious producer may create a long list of blocks forked from an earlier valid block, because there is no PoW energetic outlay required to prevent this16.

**From.** Craig Calcaterra, Wulf A. Kaal, *Secure Proof of Stake Protocol* (2018), 2.2 Soft attacks, page 9

**Cite as.** Craig Calcaterra, Wulf A. Kaal, Secure Proof of Stake Protocol (2018). SSRN: https://ssrn.com/abstract=3125827

**Verify.** sha256 of source PDF `598d9bd95e4af7a0a35328677c6bfc069f69f2e32c30c720b3a0be98a23a40cb` at https://raw.githubusercontent.com/wulfkaal/Academic-Papers/main/papers/pdf/Calcaterra%20and%20Kaal%20-%202018%20-%20Secure%20Proof%20of%20Stake%20Protocol.pdf

**Failure mode.** long-range-attack  (family: consensus-and-protocol-attack)

**Topics.** consensus-and-security

**Keywords.** long-range-attack, proof-of-stake, weak-subjectivity, fork-choice, bootstrapping

**Related claims.**

- extended_by: https://wulfkaal.github.io/claims/5225296-013

**Canonical form.** This markdown file is the canonical hashed representation of the claim. Its sha256 is the content hash used for attestation.