Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Proof-of-Stake Longest Chain Protocols: Security vs Predictability   The Nakamoto longest chain protocol is remarkably simple and has been proven
to provide security against any adversary with less than 50% of the total
hashing power. Proof-of-stake (PoS) protocols are an energy efficient
alternative; however existing protocols adopting Nakamoto's longest chain
design achieve provable security only by allowing long-term predictability
(which have serious security implications). In this paper, we prove that a
natural longest chain PoS protocol with similar predictability as Nakamoto's
PoW protocol can achieve security against any adversary with less than 1/(1+e)
fraction of the total stake. Moreover we propose a new family of longest chain
PoS protocols that achieve security against a 50% adversary, while only
requiring short-term predictability. Our proofs present a new approach to
analyzing the formal security of blockchains, based on a notion of
adversary-proof convergence.

22
The categories of this paper are: chao-dyn
28
The categories of this paper are: alg-geom
10
The categories of this paper are: q-bio
3
The categories of this paper are: physics
36
The categories of this paper are: cmp-lg
13
The categories of this paper are: quant-ph
25
The categories of this paper are: patt-sol
29
The categories of this paper are: funct-an
15
The categories of this paper are: nucl-ex
35
The categories of this paper are: mtrl-th
6
The categories of this paper are: astro-ph
37
The categories of this paper are: supr-con
9
The categories of this paper are: nlin
14
The categories of this paper are: math-ph
23
The categories of this paper are: solv-int
4
The categories of this paper are: cond-mat