Marc Girault Philippe Toffin Brigitte Vallée Computation of Approximate L-th Roots Modulo <i>n</i> and Application to Cryptography. 100-117 http://dx.doi.org/10.1007/0-387-34799-2_9 1988 conf/crypto/1988 CRYPTO db/conf/crypto/crypto88.html#GiraultTV88