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In a system including a postage printing device and a data center, wherein the postage printing device and the data center have a first set of keys for use in requesting and downloading a plurality of postage data records from the data center for use in printing postal indicia, a method of securely

In a system including a postage printing device and a data center, wherein the postage printing device and the data center have a first set of keys for use in requesting and downloading a plurality of postage data records from the data center for use in printing postal indicia, a method of securely transferring the postage printing device and any postage value stored therein from a first user to a second user. According to the method, a new set of keys for requesting and downloading postage data records is generated, any current postage value stored in the printer device is securely transferred to the second user using the new keys and some of the first set of keys, and the first set of keys is zeroed, thereby protecting the first user from any potential theft or fraud of postage funds on the part of the second user.

대표청구항 ▼

1. A method of securely transferring first data records stored in a postage printing device from a first user to a second user when said postage printing device is transferred from said first user to said second user, said postage printing device using a first key to digitally sign one or more first

1. A method of securely transferring first data records stored in a postage printing device from a first user to a second user when said postage printing device is transferred from said first user to said second user, said postage printing device using a first key to digitally sign one or more first requests for a plurality of said first data records from a data center, each of said first data records including indicium information for enabling said postage printing device to print a postal indicium, said data center using a second key to encrypt at least the indicium information of each of said first data records to generate a plurality of encrypted indicium information portions, using each of said encrypted indicium information portions to form a plurality of encrypted first data records, and using a third key to digitally sign each of said encrypted first data records to generate a plurality of data record digital signatures, said data center transmitting said encrypted first data records and said data record digital signatures to said postage printing device, said postage printing device storing said third key for authenticating each of said first data records using a corresponding one of said data record digital signatures and said second key for decrypting each of said encrypted indicium information portions of each of said encrypted first data records, the method comprising: zeroing, by said postage printing device, said first key in said postage printing device;generating, by said postage printing device and said data center, a fourth key, a fifth key and a sixth key, said postage printing device using said fourth key to digitally sign one or more second requests for a plurality of second data records from said data center, wherein each of said second data records include second indicium information for enabling said postage printing device to print a postal indicium, wherein said data center uses said fifth key to encrypt at least the second indicium information of each of said second data records to generate a plurality of encrypted second indicium information portions, using each of said encrypted second indicium information portions to form a plurality of encrypted second data records, and using said sixth key to digitally sign each of said encrypted second data records;authenticating, by said postage printing device, each of said first data records using said third key and a corresponding one of said data record digital signatures;decrypting, by said postage printing device, each of said encrypted indicium information portions of each of said encrypted first data records using said second key;encrypting, by said postage printing device, at least the indicium information of each of said first data records using said fifth key to generate a plurality of re-encrypted indicium information portions, and using each of said re-encrypted indicium information portions to form a plurality of re-encrypted first data records;digitally signing, by said postage printing device, each of said re-encrypted first data records using said sixth key; andzeroing, by said postage printing device, said second and third keys in said postage printing device. 2. The method according to claim 1, wherein said postage printing device and said data center use a first shared secret value for said first user to generate said first key and a second shared secret value for said first user to generate said second and third keys, said step of zeroing said first key including zeroing said first shared secret value for said first user in said postage printing device, said step of zeroing said second and third keys including zeroing said second shared secret value for said first user in said postage printing device, the method further comprising generating a first shared secret value for said second user at said postage printing device and said data center, and using said first shared secret value for said second user to generate a second shared secret value for said second user at said postage printing device and said data center, wherein said fourth key is generated using said first shared secret value for said second user and said fifth and sixth keys are generated using said second shared secret value for said second user. 3. The method according to claim 2, wherein said first shared secret value for said second user, said second shared secret value for said second user, and said fourth, fifth and sixth keys are generated according to ANSI X 9.63. 4. A method of transferring a postage printing device from a first user to a second user, said postage printing device and a data center having a first set of keys for use by said first user in requesting and downloading a plurality of first data records from said data center, each of said first data records including indicium information for enabling said postage printing device to print a postal indicium, the method comprising: zeroing, by said postage printing device, a first key of said first set of keys in said postage printing device, said first key being used by said postage printing device to request said first data records;generating, by said postage printing device and said data center, a second set of keys, said second set of keys for use by said second user in requesting and downloading a plurality of second data records from said data center, each of said second data records including second indicium information for enabling said postage printing device to print a postal indicium,authenticating, by said postage printing device, each of said first data records using a second key of said first set of keys;decrypting, by said postage printing device, encrypted portions of each of said first data records using a third key of said first set of keys;encrypting, by said postage printing device, at least the indicium information of each of said first data records using a first key of said second set of keys; andzeroing, by said postage printing device, said second and third keys of said first set of keys in said postage printing device.