JPH01225250A - Voice packet enciphering device - Google Patents

Abstract

PURPOSE:To secure ciphering intensity without lowering a throughput by accumulating plural voice packets to a buffer circuit and totally enciphering a long block. CONSTITUTION:The voice packet to be sent from a packet exchange 1 to voice packet enchiphering device 2 is accumulated in a buffer circuit 3. Then, when the prescribed number of the packets are accumulated, the packets are wholly transferred to an enchiphering circuit 4 as one block. The enchiphering circuit 4 cipheres this input and sends it to a MODEM line. Thus, without lowering the throughput, the enchiphering intensity can be secured.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a voice packet encryption device, and more particularly to a voice packet encryption device for encrypting voice packets in voice communications performed via a packet switching network.

[Conventional technology]

Packet switching systems are well known these days. This switching method is a type of store-and-forward method in which data sent from a terminal device is temporarily stored in the exchange and then transferred at high speed within the switching network and delivered to the terminal device of the communication partner. The data is divided into a certain length and treated as packet data in which a header containing information such as destination information, error control information, and transfer order number is added to the beginning of each divided block.

The basic configuration of a packet switching network includes a packet switch having a switching function, a packet multiplexing device having a packet assembly and division function for general terminals, and a traffic convergence function.

The packet switch sets communication routes, assembles or divides data from non-packet terminals into packet data format, and also manages and controls the system.

In addition, a packet multiplexer is a concentrator that multiplexes data from a large number of terminals in packet format on a communication line between it and a packet switch, and, similar to a packet switch, a packet multiplexer that multiplexes data from a large number of terminals in packet format on a communication line between the packet switch and the packet switch. Assembly and division are performed at a level lower than that of a packet switch.

In addition to being capable of multiplex communication, such packet-switched networks have various advantages such as improved line usage efficiency, communication between different types of terminals, and lower bit error rates, and their use is expanding. Increasingly, encrypted communications designed to keep the contents of communications confidential are also being conducted via these packet switching networks.

Conventionally, when performing encrypted communication of audio signals using a block cipher via such a packet switching network, there has been a problem in balancing the throughput of the encryption processing with the strength of the encryption.

That is, as a property of block ciphers, the encryption strength increases as the processing block length increases. If we decide to increase the processing block length to increase the encryption strength using this, the block length of the voice packet cannot be matched to the encryption block, so meaningless dummy data is added to the received data. It will be encrypted as a large block length. Then, the processing time of the block cipher increases as the block length increases, so the voice bacchio is 1
Since large block length encryption, which takes processing time, is performed each time a packet is received, throughput is significantly reduced. On the other hand, if the encrypted block length is matched to the length of the voice packet in order to increase throughput, the encryption strength will decrease. For communications other than voice communications, sacrificing throughput does not have much of an impact due to the strength of encryption, but in the case of voice packets, a decrease in encryption throughput is a problem because it leads to deterioration of sound quality.

FIGS. 2 and 3 show dimming charts for voice packet encryption by a conventional encryption device.

Figure 2 shows the case where the encrypted block length is the same as the length of the received audio packet. Although it can be used for encryption, the encryption strength is low because the encryption block length is short.

Figure 3 shows the case where the encrypted block length is increased by adding dummy data to the received voice packet. It cannot be used for encryption, but the encryption strength is increased.

[Problem to be solved by the invention]

As described above, when voice packets are encrypted using a conventional encryption device, there is a drawback that either the encryption strength or the usage efficiency of the encryption device is sacrificed.

An object of the present invention is to eliminate the above-mentioned drawbacks, and provide a voice packet encryption device that can ensure both encryption strength and usage efficiency of the encryption device by accumulating packets in a buffer and collectively encrypting them into long blocks. It's about doing.

[Means to solve the problem]

The device of the present invention is a voice packet encryption device that encrypts and transmits and receives voice packet data transmitted and received via a packet switching network, in which a plurality of voice packets are stored in a buffer circuit on a receiving side of the encryption device and are collectively lengthened. It is configured to include a means for encrypting blocks to ensure encryption strength without reducing throughput.

〔Example〕

Next, a detailed description will be given with reference to the drawings.

FIG. 1 is a block diagram showing the configuration of an embodiment of the voice packet encryption device of the present invention.

The configuration of the embodiment shown in FIG. 1 consists of a packet switch 1, a voice packet encryption device 2, and a buffer circuit 3. It consists of an encryption circuit 4.

Voice packets sent from the packet switch 1 to the voice packet encryption device 2 are accumulated in a buffer circuit 3, and when a predetermined number of packets are accumulated, all the packets are treated as one block and transferred to the encryption circuit 4.

The encryption circuit 4 encrypts this input and sends it to the modem line. The situation during this time is shown in FIG. 4 using a timing chart similar to FIGS. 2 and 3. It can be seen that the long block length takes encryption strength into consideration, and the device usage efficiency is good.

〔Effect of the invention〕

As explained above, according to the present invention, in a cryptographic device that encrypts and transmits/receives voice packet data transmitted and received via a packet switching network, a buffer is provided on the receiving side of the cryptographic device to accumulate and summarize a plurality of voice packets. By performing long block length encryption using the encryption method, it is possible to significantly improve the encryption strength without reducing the usage efficiency of the encryption device.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the configuration of an embodiment of the voice packet encryption device of the present invention, and FIG. 2 is a block diagram showing the configuration of a conventional voice packet encryption device in which the length of the encrypted block is the same as the length of the received voice packet. Encryption timing chart for case 3
The figure is an encryption timing chart in the case of a method in which gummy data is added to voice packets received by a conventional voice packet encryption device to increase the encrypted block length, and FIG. 4 is an encryption timing chart of the voice packet encryption device of the present invention. This is a timing chart. DESCRIPTION OF SYMBOLS 1...Packet switch, 2...Audio packet encryption device, 3...Buffer circuit, 4...Encryption circuit. Agent Patent Attorney Uchihara Otosa I Figure 3 V

Claims (1)

[Claims] In a voice packet encryption device that encrypts and transmits and receives voice packet data via a packet switching network, a plurality of voice packets are stored in a buffer circuit on the receiving side of the encryption device and encrypted as a long block. 1. A voice packet encryption device comprising means for ensuring encryption strength without reducing throughput.