Chase and Chow  proposed a multi-authority ABE that significantly addressed the key escrow
problem that inherently existed in ABEs, but resulted in tremendous overhead when updating keys.
Furthermore, the proposed aggregation protocol proved to be able to achieve desirable security properties including confidentiality, unforgeability, mutual authentication, anonymity, and key escrow
It offers secrecy and known-key security, and it does not suffer from the key escrow
Based on this concept, we define the model of cloud-based file transmission service (see figure 3) that is free from the key escrow
To overcome key escrow
problem of IBBE, a natural way is to adopt the corresponding approaches of IBE.
This bill would have codified the administration's export ban and started a key escrow
The 1993 introduction of Clipper, and the three similar proposals that followed, illustrates but one route attempted by the Clinton Administration to advocate development and use of key escrow
. In what could be interpreted as an attempt to force the high-tech industry to submit to governmental desires, the Clinton Administration offered to allow export of encryption software to other countries, provided that a spare set of keys was turned over to a government-approved TTP, which could then release the keys during an investigation.(76) The high-tech industry and others argued forcefully that such action notably reduced the viability of the software for export.
The key escrow
provision - a procedure under which encryption keys used to protect information have to be registered with a third party which can be accessed by police - was jettisoned after fierce lobbying by business.
Privacy advocates are skeptical of the impact government-supported key escrow
will have on their personal privacy.(57) This skepticism is heightened by the government requirement of a third party escrow holder and participation in key management.(58)
Initially, this scenario leads to the conclusion that companies should seek key escrow
systems to avoid devastating losses of information protected by strong encryption and long gone keys.
Over a four-year period, key escrow
begat key management infrastructure which begat the two twins of key recovery and trusted third parties.
The most recent development in cryptographic alternatives is the federal government's key escrow
encryption initiative, more popularly known as the Clipper Chip and the Capstone chip.