Abstract: A method and apparatus are disclosed for determining the remanent noise in a magnetic medium by, for example, dc saturation of a region thereof and measurement of the remaining dc magnetization. A conventional magnetic recording transducer may be used to determine the remanent noise. Upon determination, the remanent noise may then be digitized and stored on the same magnetic medium, in a database, or both to thereby "fingerprint" the magnetic medium. This "fingerprint" may then be later used to verify and authenticate the magnetic medium as being an original. The magnetic medium may be of a type adapted to record information magnetically or, even more broadly, any magnetic surface or substance that can be sensed through its magnetic field. In such manner, any magnetic medium, or any object having an associated magnetic medium, may be "fingerprinted" including credit cards, computer program diskettes, magneto-optic discs, videotapes, cassette tapes, bank checks, stock certificates, etc.

Abstract: Data recorded on a magnetic medium may be securely identified and manipulated for use in credit balance applications by determining a magnetic fingerprint benchmark on the medium as well as a distance between this benchmark and any pre-selected magnetic feature such as a magnetic transition of a data bit of the data set. Verification of the data may be achieved by measuring this distance and comparing it with the distance recorded at the time that the data was originally placed on the medium. As there is a detectable difference in accuracy between reading this distance as contrasted with illegitimate attempts to write false data at a pre-selected distance from the benchmark, attempts at forgery are detectable.

Abstract: A method and apparatus is disclosed or determining the remanent noise in a magnetic medium by DC saturation of a region thereof and measurement of the remaining DC magnetization. Conventional recording transducers may be used to determine the remanent noise. Upon determination, the remanent noise may then be compensated for in either or both of the record and playback modes for all varieties of magnetic media including, videotapes, cassette tapes, etc.

Abstract: A method and apparatus is disclosed for determining the remanent noise in a magnetic medium by, for example, DC saturation of a region thereof and measurement of the remaining DC magnetization. A conventional magnetic recording transducer may be used to determine the remanent noise. Upon determination, the remanent noise may then be digitized and recorded on the same magnetic medium to thereby "fingerprint" the magnetic medium. This "fingerprint" may then be later used to verify and authenticate the magnetic medium as being an original. The magnetic medium may be of a type adapted to record information magnetically or, even more broadly, any magnetic surface or substance that can be sensed through its magnetic field. In such manner, any magnetic medium, or any object having an associated magnetic medium, may be "fingerprinted" including credit cards, computer program diskettes, magneto-optic discs, videotapes, cassette tapes, bank checks, stock certificates, etc.

Abstract: A method and apparatus is disclosed for determining the remanent noise in a magnetic medium by DC saturation of a region thereof and measurement of the remaining DC magnetization. A conventional magnetic recording transducer may be used to determine the remanent noise. Upon determination, the remanent noise may then be digitized and recorded on the same magnetic medium to thereby "fingerprint" the magnetic medium. This "fingerprint" may then be later used to verify and authenticate the magnetic medium as being an original. In such manner, any magnetic medium, or any object having an associated magnetic medium, may be "fingerprinted" including credit cards, computer programs, compact discs, videotapes, cassette tapes, etc.

Abstract: A method and apparatus is disclosed for using the remanent noise of a magnetic medium as a fingerprint for benchmark testing of the magnetic medium as it is both manufactured and used. A cross-correlation is made between the fingerprint at various times as the magnetic medium is manipulated and is indicative of the integrity thereof. This cross-correlation media may be used to control manufacturing and recording processes, including tape tensioning and channel equalization. This cross-correlation between fingerprints can be used to control the tension applied to a thin film magnetic medium during record and/or playback.

Abstract: A method and apparatus is disclosed for determining the remanent noise in a magnetic medium by DC saturation of a region thereof and measurement of the remaining DC magnetization. A conventional magnetic recording transducer may be used to determine the remanent noise. Upon determination, the remanent noise may then be digitized and recorded on the same magnetic medium to thereby "fingerprint" the magnetic medium. This "fingerprint" may then be later used to verify and authenticate the magnetic medium as being an original. In such manner, any magnetic medium, or any object having an associated magnetic medium, may be "fingerprinted" including credit cards, computer programs, compact discs, videotapes, cassette tapes, etc.