This invention relates to a method and apparatus for recording audio information in an authenticatable, tamper-proof manner.
Traditionally, written documents have been used to provide permanent records of transactions and agreements. One example of this type of document is a contract for the sale of an item, which typically identifies the name of the parties, the date, the subject matter of the contract, and a price. The contract provides a permanent record that can be used at a later date to establish the terms of the agreement between the parties.
Oral contracts, on the other hand, do not provide a permanent record of the terms of the agreement. As a result, if a dispute arises over the terms of the agreement at a later date, it becomes difficult to prove exactly what the parties agreed to, or whether they made a binding contract at all. Because there is no permanent record, an unscrupulous party could be untruthful about the agreed-upon terms to escape his obligations. Even absent dishonesty, parties to an oral contract may have different recollections of exactly what they agreed to. Moreover, one of the persons who entered into the agreement may be permanently or temporarily unavailable. These problems tend to worsen as time passes.
Because of these problems, all states have statutes declaring that certain oral agreements are unenforceable, typically including the sale of land, and the sale of goods exceeding a certain value. If a trustworthy record of an oral agreement or transaction could be obtained, however, the problems of oral agreements could be overcome.
Existing methods of recording conversations, however, do not address these problems. For example, telephone answering machines, tape recorders, and handheld digital audio recording devices can be used to record a voice or a conversation. It is, however, relatively easy to delete or to alter the recorded audio information. In particular, readily available electronic devices can splice sections out of an audio conversation, and can even rearrange words to make it appear that a party said something that was never actually said. Moreover, there is no effective way for parties to sign an audio recording. As a result, it may be difficult to identify the parties that actually agreed to the terms contained in an audio conversation and intended to abide by such terms. Further, there is no way known to applicants to verify that an oral negotiation matured into an agreement.
In addition, existing telephone answering machines and tape recorders do not provide a reliable indication of when the conversation occurred. While some answering machines do record the time a call was received, this “time stamp” is extremely unreliable because a party could rerecord a new time over the time recorded by the answering machine. Alternatively, a party might either intentionally or accidentally set the date on an answering machine incorrectly. This would allow two corroborating parties to pretend that they made an agreement on a certain date, even though the agreement was not made until a later date. As a result, telephone answering machines and ordinary cassette recorders do not alleviate the problems of oral agreements described above.
STEN-TEL is an example of a system designed specifically for recording telephonic audio information. STEN-TEL is available from Sten-tel Inc. (having a place of business at 66 Long Wharf, Boston, Mass. 02110). To use STEN-TEL, a person places a telephone call to the STEN-TEL server, and the server digitally records the telephone call. After the digital recording is made, a transcriptionist accesses the recording and generates a typed record of the telephone call. The typed transcription is then uploaded to the server, where it is stored. Permanent storage of the digitally recorded audio conversation is optional. After the transcription is stored in the server, it can be downloaded to the users. Every transcription is assigned a unique identification number, and all status information is maintained in a centralized database.
The STEN-TEL system does not, however, overcome the drawbacks of existing telephone answering machines and audiocassette recorders. First, the ability to restrict access to files is limited or non-existent. Apparently any person who has the file identifier can access the stored information. Second, the information is vulnerable to tampering. Third, although STEN-TEL apparently stores the time of the call, time stamps are not embedded into the stored information. This makes STEN-TEL vulnerable to modifications of the stored date for a given conversation. Finally, digital signatures are not used to provide security and/or authenticate the parties.
One system that does incorporate certain security features is described in U.S. Pat. No. 5,594,798 (Cox et al.), which describes a voice messaging system. In Cox's system, however, an encryption key is stored along with the encrypted message. Because a hacker could obtain access to the encrypted message by retrieving the encryption key, Cox's system is vulnerable to attack. In addition, Cox's system is intended for use with secure telephone devices (STD). Ordinary telephones cannot call into Cox's system to have an audio message recorded.
No existing audio recording system is known to applicants that facilitates the permanent recording of an audio conversation in an authenticatable form so that a user can simply place a telephone call to a central server and have the server encrypt the conversation and record the time of the conversation, all in a tamper-proof manner.