Ideally, data is encrypted at the CPU (or coprocessor or TPU chip) and sent to the drive encrypted. The drive never gets the key, its only job is to store encry

Ideally, data is encrypted at the CPU (or coprocessor or TPU chip) and sent to the drive encrypted. The drive never gets the key, its only job is to store encrypted blocks correctly. In the TPU case, the TPU chip controls decryption and the key never leaves the specialized, tamper-resistant chip; wiping means sending a command to the TPU to rotate keys, thus instantly destroying any access to the data.