具有电路切换功能的电话传真加解密系统硬件设计
摘要
近年来,随着电话和传真机的广泛应用,通信安全隐患逐渐显露出来。本文在前期加解密系统的基础上,对系统中存在的不足提出了改进意见和方法,并且在实验室中对这种方法进行了验证,完成了一种具有明、密文切换功能的电话传真加密系统的硬件设计。
本文采用分别设计电话和传真的方法,对电话和传真安全方面存在的问题加以改进。设计了以3DES算法为基础的一套电话传真加解密系统,根据用户的要求在设计上进行了改进。通过分析电话通话原理,提出了设计方案,使本系统在电话通话过程中有明文、密文切换功能,使通话双方在选择方式上更加灵活和便捷。
本系统采用单片机作为主控单元,用单片机完成按键检测、数据传输、调制解调器(MODEM)控制、修改密钥等功能,通过现场可编程门阵列(FPGA)完成对语音和传真信号的3DES加解密算法。采用所设计的加解密系统,能较好的解决电话、传真的保密问题,避免了由于窃听所造成信息泄露等问题的严重后果。经过实际应用,证明了本系统可用于各个场合的保密通话,不受时间、空间的限制,只要双方持有本设备,即可完成保密通话。
Telephone and fax technologies are increasingly used, and security issues are more and more important within communication. This dissertation shows the progress on the early encryption system. This method has been evaluated in experiments. We have designed the hardware of th encryption system which can switch automatically between the encryption state and the decryption state.
We design the telephone encryption system and fax encryption system separately. To improve the security of communication, an encrypt system based on 3DES algorithm is described in this dissertation. We have made losts of progress according to the users.We design the system whitch can work in decrypting way or in encrypting way. Both spekers use this system conveniently.
The system can work in control of the MCU which can control other integrated circuits such as MODEM. The FPGA can make the decrypting digital singal into encrypting singals according to 3DES algorithm. The system can resolve the communition security problem. This telephone encrypt system has been implemented successfully and performs well, and can be used widely. The system has been validated on the PSTN (Public Switched Telephone Network). It has indicated that the voice transmitted is clear and that the quality and the speed of the fax is ensured to a haigh stand. In the meantime, telephones can still work as normally.
本文采用分别设计电话和传真的方法,对电话和传真安全方面存在的问题加以改进。设计了以3DES算法为基础的一套电话传真加解密系统,根据用户的要求在设计上进行了改进。通过分析电话通话原理,提出了设计方案,使本系统在电话通话过程中有明文、密文切换功能,使通话双方在选择方式上更加灵活和便捷。
本系统采用单片机作为主控单元,用单片机完成按键检测、数据传输、调制解调器(MODEM)控制、修改密钥等功能,通过现场可编程门阵列(FPGA)完成对语音和传真信号的3DES加解密算法。采用所设计的加解密系统,能较好的解决电话、传真的保密问题,避免了由于窃听所造成信息泄露等问题的严重后果。经过实际应用,证明了本系统可用于各个场合的保密通话,不受时间、空间的限制,只要双方持有本设备,即可完成保密通话。
Telephone and fax technologies are increasingly used, and security issues are more and more important within communication. This dissertation shows the progress on the early encryption system. This method has been evaluated in experiments. We have designed the hardware of th encryption system which can switch automatically between the encryption state and the decryption state.
We design the telephone encryption system and fax encryption system separately. To improve the security of communication, an encrypt system based on 3DES algorithm is described in this dissertation. We have made losts of progress according to the users.We design the system whitch can work in decrypting way or in encrypting way. Both spekers use this system conveniently.
The system can work in control of the MCU which can control other integrated circuits such as MODEM. The FPGA can make the decrypting digital singal into encrypting singals according to 3DES algorithm. The system can resolve the communition security problem. This telephone encrypt system has been implemented successfully and performs well, and can be used widely. The system has been validated on the PSTN (Public Switched Telephone Network). It has indicated that the voice transmitted is clear and that the quality and the speed of the fax is ensured to a haigh stand. In the meantime, telephones can still work as normally.
引文
[1]胡晓勤,通用PSTN安全电话的研究与实现,四川:四川大学,2004
[2]吴世忠,应用密码学,北京:机械工业出版社,2003
[3]桂海源,现代交换原理,北京:人民邮电出版社,2005,1-11.
[4]连林珍,基于无线信道的语音编码压缩,软件导刊,2005,20:22-24
[5]王秀玲,基于DTMF的智能电话控制器设计,现代电子技术,2007,259(20):189-191
[6]应明仁,王化成,单片机原理与应用,广州:华南理工大学出版社,2005
[7]王铁生,DCME中的传真解调与再调制技术,南京:南京邮电学院,2001
[8]王招迎,一种基于PSTN的新型语音保密系统,北京电子科技学院学报,2006,14(4),57-59
[9]张顺颐,传真通信技术基础,北京:电子工业出版社,1994.5,65-106
[10]徐惠民,安德宁,数字逻辑设计与VHDL描述,北京:机械工业出版社,2002
[11]怀石工作室.MODEM完全手册,北京:中国电力出版社,2000
[12] I-56SRT/M-56RST嵌入式调制解调器技术标准书
[13]Ultra-High-Speed FlashMicrocontroller User’s Guide
[14]DS89C420 Ultra-High-Speed Microcontroller
[15]HC5503 data sheet. 2004. 6
[16]TP3054B, TP3057B, TP13054B, TP13057B MONOLITHIC SERIAL INTERFACE COMBINED PCM CODEC AND FILTER
[17]DS2165/DS2165Q16/24/32kpbs ADPCM Processor
[18]MAX232, MAX232I DUAL EIA-232 DRIVER/RECEIVER. 1995.5
[19]X25043/45 Programmable Watchdog Supervisory E2PROM.
[20]AT Commands for Central Site Modems. 1997-8-29
[21]Using the High-Speed Micro's Watchdog Timer. 2001-3-29
[2]吴世忠,应用密码学,北京:机械工业出版社,2003
[3]桂海源,现代交换原理,北京:人民邮电出版社,2005,1-11.
[4]连林珍,基于无线信道的语音编码压缩,软件导刊,2005,20:22-24
[5]王秀玲,基于DTMF的智能电话控制器设计,现代电子技术,2007,259(20):189-191
[6]应明仁,王化成,单片机原理与应用,广州:华南理工大学出版社,2005
[7]王铁生,DCME中的传真解调与再调制技术,南京:南京邮电学院,2001
[8]王招迎,一种基于PSTN的新型语音保密系统,北京电子科技学院学报,2006,14(4),57-59
[9]张顺颐,传真通信技术基础,北京:电子工业出版社,1994.5,65-106
[10]徐惠民,安德宁,数字逻辑设计与VHDL描述,北京:机械工业出版社,2002
[11]怀石工作室.MODEM完全手册,北京:中国电力出版社,2000
[12] I-56SRT/M-56RST嵌入式调制解调器技术标准书
[13]Ultra-High-Speed FlashMicrocontroller User’s Guide
[14]DS89C420 Ultra-High-Speed Microcontroller
[15]HC5503 data sheet. 2004. 6
[16]TP3054B, TP3057B, TP13054B, TP13057B MONOLITHIC SERIAL INTERFACE COMBINED PCM CODEC AND FILTER
[17]DS2165/DS2165Q16/24/32kpbs ADPCM Processor
[18]MAX232, MAX232I DUAL EIA-232 DRIVER/RECEIVER. 1995.5
[19]X25043/45 Programmable Watchdog Supervisory E2PROM.
[20]AT Commands for Central Site Modems. 1997-8-29
[21]Using the High-Speed Micro's Watchdog Timer. 2001-3-29