In this paper, we show that two variants of Stern's identification scheme [IEEE Transaction on Information Theory '96] are provably secure against concurrent attack under the assumptions on the worst-case hardness of lattice problems. These assumptions are weaker than those for the previous lattice-based identification schemes of Micciancio and Vadhan [CRYPTO '03] and of Lyubashevsky [PKC '08]. We also construct efficient ad hoc anonymous identification schemes based on the lattice problems by modifying the variants.