Patent ID: 7739518

Claim:
A method for securing a cable modem (CM) following Data Over Cable Service Interface Specification (DOCSIS) against physical security attacks, comprising the steps of: a) classifying information to be stored in the DOCSIS CM based on a requirement degree of confidentiality and anti-alteration; b) storing the classified information in a non-volatile memory of the DOCSIS CM when the information is absolute confidential information, but processing a mechanism for deleting the information stored in the non-volatile memory in case that attacks by a hacker is sensed; c) storing the classified information in the non-volatile memory of the DOCSIS CM when the information is middle-level security information; and d) storing the classified information in a write-once (WO) memory of the DOCSIS CM when the information is absolute anti-alteration information, wherein a security level of the absolute anti-alteration information does not exceed level 1 of the Federal Information Processing Standards Publication 140-2 (FIPS PUB 140-2).