What is a BitLocker Drive Encryption startup key or PIN?
When you use BitLocker Drive Encryption, you need a BitLocker Drive Encryption startup key or personal identification number (PIN) to start your computer. BitLocker stores its own encryption and decryption keys in a hardware device called the Trusted Platform Module (TPM) security hardware, which is a special microchip in some newer computers that supports advanced security features. The keys are not stored on the computer’s hard disk. The TPM must be accessible by the basic input/output system (BIOS) during startup. When you start your computer, BitLocker will get these keys from the TPM automatically.
