# what is SALSA20 Nonce and its requirements [duplicate]

what is the source of nonce in SALSA20 algorithm. basically who provides the value of nonce in SALSA20 algorithm

• – CodesInChaos Nov 10 '14 at 12:15

An addition warning if you're using the asymmetric box function: Both directions (A->B and B->A) generate the same XSalsa20 key so a nonce used in one direction must not be reused in the other direction. Typically that's achieved by either using different keys for both directions or by use non overlapping nonce spaces.