SHA-256 is the recommended stronger alternative to SHA-1. See FIPS PUB 180-4 for implementation details.

Either by using a dedicated library or implementing the algorithm in your language, show that the SHA-256 digest of the string "Rosetta code" is: 764faf5c61ac315f1497f9dfa542713965b785e5cc2f707d6468d7d1124cdfcf

;; using the crypto module from http://www.newlisp.org/code/modules/crypto.lsp.html
;; (import native functions from the crypto library, provided by OpenSSL)
(module "crypto.lsp")
(crypto:sha256 "Rosetta Code")