Key management for encrypted packet based networks

Claim 3

The method of claim 1, wherein said network service provider includes a key management center and wherein said transparent device includes a data encryption device, and further comprising the step of: transmitting a cryptographic key from said key management center to said data encryption device.

Claim 4

The method of claim 2, further comprising the step of transmitting a cryptographic key to said target DTE.

Claim 5

The method of claim 1, wherein said balancing step includes the steps of transmitting an interrupt request packet from said transparent device to said source DTE and transmitting an interrupt confirm packet from said source DTE to said transparent device.

Claim 6

The method of claim 1, wherein said balancing step includes the steps of transmitting a call request packet for a fictitious address from said transparent device to said source DTE, transmitting a clear request packet from said source DTE to said transparent device and transmitting a clear confirm packet from said transparent device to said source DTE.

Claim 7

The method of claim 1, wherein said intercepting step includes the step of intercepting a call setup packet from said source DTE destined for said target DTE and substituting a fast select packet to said network service provider in its place.

Claim 8

In a packet switched network coupled to a first Data Terminal Equipment (DTE) and a second DTE with a first and a second transparent device coupled between said first and second DTE's and said packet switched network respectively, and a network service provider coupled to said packet switched network, and wherein a transparent device being defined as a network device which is not addressable by other network devices by a network address, a method for balancing traffic through said transparent device in order to make frame send and receive sequence numbers equal and packet send and receive sequence numbers equal comprising the steps of: transmitting a dummy packet from said first transparent device to said first DTE; and responding with a response packet from said first DTE to said transparent device.

Claim 9

In a packet switched network coupled to a first Data Terminal Equipment (DTE) and a second DTE with a first and a second transparent device coupled between said first and second DTE's and said packet switched network respectively, and a network service provider coupled to said packet switched network, and wherein a transparent device being defined as a network device which is not addressable by other network devices by a network address, a method for balancing traffic through said transparent device in order to make frame send and receive sequence numbers equal and packet send and receive sequence numbers equal comprising the steps of: transmitting a dummy packet from said first transparent device to said first DTE; and responding with a response packet from said first DTE to said transparent device.

Claim 10

The method of claim 7, wherein: said transmitting step includes transmitting an interrupt packet; and wherein: said responding step includes responding with an interrupt confirmation packet.

Claim 11

The method of claim 7, wherein: said transmitting step includes transmitting a call request packet to a fictitious address; and wherein: said responding step includes responding with a clear request packet; and further comprising the step of: sending a clear confirmation packet from said transparent device to said first DTE.

Claim 12

In a packet switched network, method for changing keys used for encrypted switched virtual circuit communication between a first Data Terminal Equipment (DTE) and a second DTE, said first and second DTE having an associated first and second encryption device, comprising the steps of: issuing a call request packet from said first DTE to said second DTE; intercepting said call request packet at said first encryption device and substituting a call request for a key management center; transferring a key from said key management center to said first DTE; balancing counters at a link associated with said first DTE and first encryption device using a dummy packet in order to make frame send and receive sequence numbers equal and packet send and receive sequence numbers equal; establishing a channel between said first and second data encrypters; and transferring a key from said first data encrypter to said second encrypter.

Claim 13

In a packet switched network, method for changing keys used for encrypted switched virtual circuit communication between a first Data Terminal Equipment (DTE) and a second DTE, said first and second DTE having an associated first and second encryption device, comprising the steps of: issuing a call request packet from said first DTE to said second DTE; intercepting said call request packet at said first encryption device and substituting a call request for a key management center; transferring a key from said key management center to said first DTE; balancing counters at a link associated with said first DTE and first encryption device using a dummy packet in order to make frame send and receive sequence numbers equal and packet send and receive sequence numbers equal; establishing a channel between said first and second data encrypters; and transferring a key from said first data encrypter to said second encrypter.

Claim 14

In a packet switched network, method for changing keys used for encrypted permanent virtual circuit communication between a first Data Terminal Equipment (DTE) and a second DTE, said first and second DTE having an associated first and second encryption device, comprising the steps of: issuing a call request packet from a key management center to said first encryption device; issuing a call request packet from said key management center to said second encryption device; from said key management center, sending a stop packet flow message from said first DTE to said second DTE and obtaining a last MAC from said first data encryption device and transferring a new key to said first data encryption device; from said key management center, sending a stop packet flow message from said second DTE to said first DTE and obtaining a last MAC from said second data encryption device and transferring a new key to said first data encryption device; from said key management center, sending a restart packet flow message to restart packet flow between said first and second DTE; and balancing link counters at said first and second links by transmission of dummy packets in order to make frame send and receive sequence numbers equal and packet send and receive sequence numbers equal.

Claim 15

In a packet switched network, method for changing keys used for encrypted permanent virtual circuit communication between a first Data Terminal Equipment (DTE) and a second DTE, said first and second DTE having an associated first and second encryption device, comprising the steps of: issuing a call request packet from a key management center to said first encryption device; issuing a call request packet from said key management center to said second encryption device; from said key management center, sending a stop packet flow message from said first DTE to said second DTE and obtaining a last MAC from said first data encryption device and transferring a new key to said first data encryption device; from said key management center, sending a stop packet flow message from said second DTE to said first DTE and obtaining a last MAC from said second data encryption device and transferring a new key to said first data encryption device; from said key management center, sending a restart packet flow message to restart packet flow between said first and second DTE; and balancing link counters at said first and second links by transmission of dummy packets in order to make frame send and receive sequence numbers equal and packet send and receive sequence numbers equal.