Table 2.

Multilevel security system.

Classification	Class I		Class II	Class III
Sensitivity	High		Moderate	Low
Level of security	High		Moderate	Base
Access control
Operation and authentication
Read	Three-factor authentication (e.g., password, security token, and biometric identifier)		Two-factor authentication (e.g., password and security token)	Single factor authentication (e.g., password or personal identification number)
Write	Three-factor authentication + signature + OTP		Two-factor authentication + signature	Single factor authentication + signature
Encryption security
Segment	Normal data	Critical data, mapping data	The entire data	The entire data
Algorithm	Simple encryption (e.g., symmetric substitution algorithm)	Industry standard encryption (e.g., AES, RC4 algorithm)	Industry standard encryption (e.g., blowfish algorithm)	Simple encryption (e.g., symmetric substitution algorithm)