var sha256d = require'sha256d'var hash = sha256dupdate'hello' 'ascii'digest'hex'console.loghash//9595c9df90075148eb06860365df33584b75bff782a510c6cd4883a419833d50
sha1 is no longer considered secure, and should not be used in new cryptosystems. recent attacks have been developed which weaken sha1 significantly, from 2^80 to 2^69 attempts to find a collision.
Schiener estimates that by 2021 it could cost as little at 41k usd to generate a sha1 collision.
Also, Merkle–Damgård constructions, such as the sha1 and sha2
family of algorithms also are succeptable to a
this means that if you know
x = sha(y) you can calculate
x2 = sha(y + z) without knowing
This may or may not be a problem in your system, but there is no harm in being belt and suspenders safe.