In a general aspect, pseudorandom integers are generated for use in a cryptographic protocol. In some aspects, a first plurality of digits are obtained and converted to a second plurality of digits. The first plurality of digits (e.g., bits) represent an integer in a first number system (e.g., binary), and the second plurality of digits (e.g., trits) represent the integer in a second number system (e.g., trinary). A plurality of integers in the first number system are generated based on the second plurality of digits, and an array of integers is produced. Each integer in the array is less than a modulus, and the array includes the plurality of integers. The array of integers can be used in a lattice-based cryptographic protocol.