Lenovo ThinkVantage Client Security Solution 8.3 - Manual (Page 84)

Symmetric-key encryption Symmetric key encryption ciphers use the same key
for encryption and decryption of data. Symmetric
key ciphers are simpler and faster, but their main
drawback is that the two parties must somehow
exchange the key in a secure way. Public-key
encryption avoids this problem because the
public key can be distributed in a non-secure
way, and the private key is never transmitted.
Advanced Encryption Standard is an example of a
symmetric-key.
Trusted Platform Module (TPM) Trusted Platform Modules are special-purpose
integrated circuits built into systems to enable
strong user authentication and machine verification.
The main purpose of the TPM is to prevent
inappropriate access to confidential and sensitive
information. The TPM is a hardware based root of
trust that can be leveraged to provide a variety of
cryptographic services on a system. Another name
for TPM is the embedded security chip.