Methods are described that facilitate the detection and correction of data in memory systems or devices by encoding the data bits of a memory row or block in a non-systematic ECC code. Reduced complexity error detection and correction hardware and/or routines detect and correct corrupted user data in a segment of memory, such as a sector, word line row, or erase block. User data is not stored in a plaintext format in the memory array. The ECC code is distributed throughout the stored data in the memory segment.