This book constitutes the proceedings of the First International Conference on Cryptology and Information Security in Latin America, LATINCRYPT 2010, held in Puebla, Mexico, on August 8-11, 2010. The 19 papers presented together with four invited talks were carefully reviewed and selected from 62 submissions. The topics covered are encryption, elliptic curves, implementation of pairings, implementation of cryptographic algorithms, cryptographic protocols and foundations, cryptanalysis of symmetric primitives, post-quantum cryptography, and side-channel attacks.