Erik Dahmen Katsuyuki Okeya Tsuyoshi Takagi Camille Vuillaume Digital Signatures Out of Second-Preimage Resistant Hash Functions. 109-123 2008 PQCrypto http://dx.doi.org/10.1007/978-3-540-88403-3_8 conf/pqcrypto/2008 db/conf/pqcrypto/pqcrypto2008.html#DahmenOTV08