Systems and methods for media authentication
View Patent ↗A method and system for authenticating a digital optical medium, such as a CD-ROM, determine whether the medium is an unauthorized copy, or the original. The original media is created, or altered, so as to contain anomalous locations from which the transfer of data is accomplished at different rates than a standard digital copy would exhibit. One implementation of the process involves timing analysis of the differences in data transfer rates. Another implementation involves the determination of digital signatures during multiple read operations performed on a data segment. The process can be employed in systems that control access to unauthorized copies, or may be used for other informative purposes. Theft, distribution, and piracy of digital content on optical media, such as computer software (also games, video, audio, e-book content), is often accomplished by copying it directly to another disc using commonly available copy tools and recordable optical media, or the replication of media to another mass manufactured disc. The present invention, which helps to irrefutably identify a unit of optical media as the original, and can correspondingly identify any copy made by any currently available means as such a copy, may prevent an unauthorized individual from making use of any unauthorized copies. This offers significant advantages to content creators who wish to protect their products.
1. A method for authenticating a removable digital medium by determining the presence of an anomaly region corresponding to a data segment of the removable digital medium comprising: performing multiple read operations on a data segment of the removable digital medium to generate multiple corresponding read data results; calculating corresponding digital signatures using actual data values of underlying data of the read data segment for each of the multiple read data results; determining whether an anomaly region is present in the data segment based on a comparison of the digital signatures by determining whether any of the digital signatures are equal in value, and if a predetermined number of the digital signatures are not equal in value, determining the anomaly region to be present; and authenticating the removable digital medium in response to the determination of the presence of the anomaly region.
2. The method of claim 1 wherein the data comprises data selected from the group consisting of: user data, error data, sync data, parity data, header data, and sub-channel data.
3. The method of claim 1 further comprising monitoring a transfer rate of the read data during at least one of the read procedures, and further determining whether an anomaly region is present in the data segment based on the monitored transfer rate.
4. The method of claim 1 further comprising:
first monitoring a first transfer rate of first read data during one of the read procedures, and further determining whether an anomaly region is present in the data segment based on the monitored first transfer rate; and
in the event that the presence of an anomaly is not determined as a result of the first monitoring, second monitoring a second transfer rate of second read data during another of the read procedures, and further determining whether an anomaly region is present in the data segment based on the monitored second transfer rate.
5. The method of claim 1 wherein calculating corresponding digital signatures for each of the multiple read data results comprises calculating a digital signature selected from the group consisting of message digest algorithm 2 (MD2), message digest algorithm 4 (MD4), message digest algorithm 5 (MD5), Snefru, secure hash algorithm (SHA), National Institute of Standards and Technology digital signature algorithm (NIST DSA), Haval, N-Hash, and RACE integrity primitives evaluation message digest (RIPE-MD) digital signatures.
6. The method of claim 1 further comprising, if none of the digital signatures are equal in value, determining the anomaly region to be present.
7. A system for authenticating a removable digital medium by determining the presence of an anomaly region corresponding to a data segment of the removable digital medium comprising: a read unit for performing multiple read operations on a data segment of the removable digital medium to generate multiple corresponding read data results; a calculating unit for calculating corresponding digital signatures using actual data values of underlying data of the read data segment for each of the multiple read data results; and a determining unit for determining whether an anomaly region is present in the data segment based on a comparison of the digital signatures by determining whether any of the digital signatures are equal in value, and if a predetermined number of the digital signatures are not equal in value, the determining unit determining the anomaly region to be present; and a means for authenticating the removable digital medium in response to the determination of the presence of the anomaly region.
8. The system of claim 7 wherein the data comprises data selected from the group consisting of: user data, error data, sync data, parity data, header data, and sub-channel data.
9. The system of claim 7 further comprising a rate monitoring unit for monitoring a transfer rate of the read data during at least one of the read procedures, and further determining whether an anomaly region is present in the data segment based on the monitored transfer rate.
10. The system of claim 7 further comprising:
a monitoring unit for first monitoring a first transfer rate of first read data during one of the read procedures, and further determining whether an anomaly region is present in the data segment based on the monitored first transfer rate; and, in the event that the presence of an anomaly is not determined as a result of the first monitoring, second monitoring a second transfer rate of second read data during another of the read procedures, and further determining whether an anomaly region is present in the data segment based on the monitored second transfer rate.
11. The system of claim 7 wherein the calculating unit calculates a digital signature selected from the group consisting of message digest algorithm 2 (MD2), message digest algorithm 4 (MD4), message digest algorithm 5 (MD5), Snefru, secure hash algorithm (SHA), National Institute of Standards and Technology digital signature algorithm (NIST DSA), Haval, N-Hash, and RACE integrity primitives evaluation message digest (RIPE-MD) digital signatures.
12. The system of claim 7 wherein, if none of the digital signatures are equal in value, the anomaly region is determined to be present.