发明名称 |
Secure teleconferencing |
摘要 |
Secure teleconferencing between three or more parties is achieved by receiving encrypted information streams from each of the parties to the conference. The encrypted information streams are received in decryption/re-encryption units co-located with a conference bridge established in a telecommunication switching system in a public switched telephone network central office. The decryption/re-encryption units decrypt the information streams and then re-encrypt those information streams in accordance with a common conference encryption algorithm. The re-encryption processes for the information streams are synchronized so that the re-encryption circuitry for all information streams are in the same cryprostate at all times during the re-encryption procedure. The decryption/re-encryption units are located in secure surroundings to protect the unencrypted information streams present in those units. A gating circuit permits only one of the re-encrypted information streams to be input to the conference bridge at a given time. A circuit which simulates the operation of a silent conferee prevents noise bursts from being sent to the conferees during periods of time when all are silent.
|
申请公布号 |
US5353351(A) |
申请公布日期 |
1994.10.04 |
申请号 |
US19920896520 |
申请日期 |
1992.06.09 |
申请人 |
AT&T BELL LABORATORIES |
发明人 |
BARTOLI, PAUL D.;MCNAIR, BRUCE E. |
分类号 |
H04K1/00;H04M3/56;(IPC1-7):H04L9/18 |
主分类号 |
H04K1/00 |
代理机构 |
|
代理人 |
|
主权项 |
|
地址 |
|