Implementation and Performance of Threshold Cryptography for Multiple Escrow Agents in VoIP

Abstract

This paper focuses on improving the accessibility and security of multiple escrow agents by dividing the session master key into M chunks and escrowing the chunks with M escrow agents. Using threshold cryptography the key can be regenerated by gathering any N-out-of-M chunks. This N-out-of-M approach increases the security of the session master key as at least N chunks of the session key are needed to regenerate the session key. Disclosure of less than N chunks does not threat the security of the session key. On the other hand, failure of a single escrow agent does not affect the availability of the session key as long as N escrow agents are working. For a highly sophisticated session, the user might define a higher value for M and N. For a less confidential or less important session, the value of M and N might be smaller.