Bitcoin RIPEMD160 purpose

Question

Bitcoin uses RIPEMD160 on top of SHA256. Is its sole purpose to make public key address shorter or does it strengthen security in any way?

Possible duplicate of Why does Bitcoin use two hash functions (SHA-256 and RIPEMD-160) to create an address? — Raghav Sood, Apr 26 '18 at 22:04
The question you mentioned has slightly different meaning where it asks why double hashing instead of simple SHA256. My curiosity was why use RIPEMD160 with SHA256, for ex: why not SHA256d. — Jamol, Apr 26 '18 at 22:20

score 2 · Accepted Answer · answered Apr 26 '18 at 20:47

2

RIPEMD160 was designed in the open academic community and not like SHA2 by a NSA competition... one may see this as security advantage.

160bit hashes do also have less space requirements (then sha256) on the blockchain as well as in indexes, etc.

answered Apr 26 '18 at 20:47

Jonas Schnelli

Thanks Jonas Schnelli, does it also give advantage for being used together with SHA256 in terms of double hashing? – Jamol Apr 26 '18 at 21:16
Most hashes in bitcoin are using double sha256. But an additional RIPEMD does protect against possible weakness in SHA256 since addresses are hashed with SHA256 and RIPEMD160. – Jonas Schnelli Apr 27 '18 at 20:10

1 Answers1