Patent ID: 6889210

Claim:
In a system for providing restrictive access to contents in secured files, each of the secured files classified in accordance with one of N security levels, a method for reorganizing the N security levels without implicating accessibilities to the secured files, the method comprising: determining a new security level with respect to the N security levels, wherein a 1st security level is most restrictive and an Nth security level is least restrictive in the N security levels; generating security parameters accordingly for the new security level, the new security level being ith less restrictive with respect to the 1st security level; and mapping ith security level in the N security levels to (i+1)th security level in the N security levels to accommodate the new security level such that there are now (N+1) security levels in the system, wherein each of the secured files includes an encrypted data portion and a security portion that controls restrictive access to the encrypted data portion, the security portion including a file key encrypted by at least a first key and a second key and further protected by a set of rules, and wherein both of the first key and the second key must be obtained by a user whose access privilege is satisfied by the rules before the contents of the each of the secured files can be accessed.