Secured printer for a value printing system

A secure assembly for printing indicia on a document, said assembly adapted to be resonsive to an input data signal for printing information conveyed by the input data signal, the information corresponding to the indicia to be printed, at least a portion of the information being encrypted using cipher key information, said assembly comprising:

• a decrypting device for decrypting said encrypted information in accordance with cipher key information;
• a storage device for storing cipher key information, said storage device electrically connected to said decrypting device for providing thereto cipher key information;
• a print control device for controlling printing of said indicia;
• a printing mechanism connected to said decryption device and to said control device, said mechanism printing said indicia on said document in accordance with the decrypted information when said cipher key information is provided;
• and
• continuity sensing means including a communication link and means for detecting continuity of said link, said communications link providing at least a portion of said cipher key information to said decrypting device when continuity of said link is detected by said detecting means.

A method of securing against tampering a device of the type which is responsive to information conveyed thereto for causing the device to activate a desired output, at least a portion of the information being encrypted in accordance with valid cipher key information, comprising the steps of:

• providing a first portion of the valid cipher key information to the device;
• providing continuity sensing means for conveying a second portion of the valid cipher key information to the device, the continuity sensing means permitting conveyance of said second portion of the valid cipher key information when said sensing means senses continuity and interrupting conveyance of said second portion of the valid cipher key when said sensing means senses diuscontinuity;
• decrypting the encrypted portion of the conveyed information, in accordance with the first and the second portions of the valid key information;
• and
• activating the desired output in accordance with the decrypted information.

A value printing system including a secured printer assembly for the printing of indicia including a value, said system comprising a metering device including means for accounting for the value to be printed, said metering device including means for generating encrypted data in accordance with a cipher key, the encrypted data representative of the indicia to be printed, said metering device including means for providing the encrypted data and the cipher key to said printer assembly, said assembly comprising:

• decrypting means for decrypting the data in accordance with the cipher key;
• storage means for storing the cipher key, said storage means connected electrically to said decrypting means for providing the cipher key thereto;
• and
• continuity sensing means electrically connected to said storage means, said sensing means including conducting means, said sensing means including means for detecting continuity of said conducting means, said conducting means defining at least a portion of the cipher key for said storage means when continuity is sensed, and said conducting means not defining said portion of said cipher key for said storage means when continuity is not sensed. a printing mechanism operably coupled to said decryption device for printing the decrypted data whereby said indicia is printed.

A system for securing a device against invasive tampering, said device adapted to be responsive to encrypted input data for providing a desired output, said system comprising:

• decryption microcomputer means for providing decrypted data from said encrypted input data only when said microcomputer means is provided with a valid cipher key, said microcomputer means including means for providing said desired output in accordance with said decrypted data;
• storage means for storing a first portion of said valid cipher key, said storage means electrically connected to said microcomputer means for providing said first portion thereto;
• continuity sensor means electrically connected to said microcomputer means for providing a second portion of said valid cipher key thereto, said sensor means including conducting means and means for detecting continuity of said conducting means, said conducting means providing said second valid portion only when said detecting means detects continuity of said conducting means;
• and
• potting material means embedding at least said conducting means therewithin, said conducting means positioned within said potting material means such that invasive tampering with said potting material means results in said detecting means not sensing continuity of said conducting means whereby said decryption microcomputer means is not provided with said second portion of said valid cipher key thereby preventing the occurrence of said desired output.