Voice signature method. The signer obtains a public key from an intended
recipient of a document to be electronically signed. The signer speaks a
personal identification number (PIN) to generate a voice PIN and the
signer also speaks at least the signer's name. The voice PIN and voice
signature are appended to the document and the voice PIN is encrypted
using the public key to create an encrypted voice PIN. A polynomial hash
is generated based on the document, the voice signature and the encrypted
voice PIN and this hash is itself encrypted based on the PIN to generate
an encrypted hash. Finally, the document, the voice signature, the
encrypted voice PIN and the encrypted hash are sent to the intended
recipient.