A method, system, computer program product, and method of doing business by providing improved audio compression wherein an audio stream is securely transformed to an encoded text stream (such as an ASCII, EBCDIC, or Unicode text stream). One or more components which are involved in the transformation process are authenticated. A unique identifier of each such component is included within cryptographically-protected information that is provided for the encoded text stream. A digital signature is preferably used for the cryptographic protection, thereby digitally notarizing the encoded text stream. The authenticity and integrity of the encoded text stream can therefore be verified. In preferred embodiments, the authenticated identities of components performing the transformation can also be determined from the cryptographically-protected information. The encoded text stream will typically require much less storage space than the audio stream, and providing the digital notarization along with the encoded text stream serves to reliably establish evidence of the contents of the audio stream (even though a perfect speech-to-text transformation might not be achieved).