Patent US5486524A successfully refreshed from Google Patents.
Patent US6367019B1 successfully refreshed from Google Patents.
US6367019B1
Expired / Lapsed
US
⏱️ 0.0 years remaining
Copy security for portable music players
Assignee: LIOUID AUDIO Inc
•
Filing: 1999-03-26
•
Granted: 2002-04-02
•
Expires: 2019-03-26
Abstract
Abstract Data such as a musical track is stored as a secure portable track (SPT) which can be bound to one or more players and can be bound to a particular storage medium, restricting playback of the SPT to the specific players and ensuring that playback is only from the original storage medium. The SPT is bound to a player by encrypting data of the SPT using a storage key which is unique to the player, is difficult to change, and is held in strict secrecy by the player. The SPT is bound to a particular storage medium by including data uniquely identifying the storage medium in a tamper-resistant form, e.g., cryptographically signed. The SPT can also be bound to the storage medium by embedding cryptographic logic circuitry, e.g., integrate circuitry, in the packaging of the storage medium. The SPT is bound by encrypting an encryption key using the embedded logic. By using unique cryptographic logic, only that particular storage medium can decrypt the encryption key and, therefore, the data of the SPT encrypted with the encryption key. To allow a user to playback the SPT on a number of players, players can share storage keys with one another. Such key sharing is done in a cryptographically secure manner. Before downloading an SPT to a particular external player, the ability of the external player to enforce restrictions placed upon the SPT is verified.
Inventors
- 👤 Steven T. Ansell
- 👤 Andrew R. Cherenson
- 👤 Mark E. Paley
- 👤 Steven B. Katz
- 👤 John Michael Kelsey, Jr.
- 👤 Bruce Schneier
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 13:10
CPC Classifications
G; G11; G11B; G11B20/00; G11B20/00086; G06; G06F; G06F21/00; G06F21/10; G11B20/00094; G11B20/00115; G11B20/00188; G11B20/00195; G11B20/0021; G11B20/00217; G11B20/00253; G11B20/00333; G11B20/00731; G11B20/00746; G11B20/00782; G11B20/00797; G11B20/0084; G06F2211/00; G06F2211/007
Claims Analysis
Total Claims: 111
Claim 1
Independent Claim
112 words
A method for binding subject data to a selected data access device such that the subject data is inaccessible to data access devices other than the selected data access device, the method comprising: encrypting the subject data to form encrypted subject data using data corresponding to the selected data access device as an encryption key; forming key identification data from the encryption key; and storing the encrypted subject data and the key identification data in a storage medium which is readable by the selected data access device; wherein the encryption key is not directly determinable from data stored on the storage medium including the key identification data and the encrypted subject data.
Claim 2
Independent Claim
112 words
A method for binding subject data to a selected data access device such that the subject data is inaccessible to data access devices other than the selected data access device, the method comprising: encrypting the subject data to form encrypted subject data using data corresponding to the selected data access device as an encryption key; forming key identification data from the encryption key; and storing the encrypted subject data and the key identification data in a storage medium which is readable by the selected data access device; wherein the encryption key is not directly determinable from data stored on the storage medium including the key identification data and the encrypted subject data.
Claim 3
Dependent Claim
34 words
The method of claim 1 wherein encrypting the subject data comprises: encrypting the subject data using a master key; and encrypting the master key with the encryption key to form an encrypted master key.
Claim 4
Dependent Claim
27 words
The method of claim 2 wherein storing the encrypted subject data and the key identification data further comprises: storing the encrypted master key in the storage medium.
Claim 5
Dependent Claim
31 words
The method of claim 3 further comprising: forming message verification data using the key identification data and the encrypted master key; and storing the message verification data in the storage medium.
Claim 6
Dependent Claim
16 words
The method of claim 4 wherein the message verification data is a message authentication code (MAC).
Claim 7
Dependent Claim
26 words
The method of claim 1 further comprising: forming message verification data using the key identification data; and storing the message verification data in the storage medium.
Claim 8
Dependent Claim
16 words
The method of claim 6 wherein the message verification data is a message authentication code (MAC).
Claim 9
Dependent Claim
13 words
The method of claim 1 wherein the subject data includes digitized audio signals.
Claim 10
Dependent Claim
18 words
The method of claim 1 wherein the data secretly held by the selected data access device is read-only.
Claim 11
Independent Claim
115 words
A method for accessing subject data from a storage medium by a selected data access device, the method comprising: retrieving key identification data from the storage medium; determining that the key identification data corresponds to data secretly held by the selected data access device; retrieving encrypted subject data from the storage medium; and decrypting the encrypted subject data using the data secretly held by the selected data access device as an encryption key to form the subject data wherein the key identification data is formed from the encryption key; and wherein the encryption key is not directly determinable from data stored on the storage medium including the key identification data and the encrypted subject data.
Claim 12
Independent Claim
115 words
A method for accessing subject data from a storage medium by a selected data access device, the method comprising: retrieving key identification data from the storage medium; determining that the key identification data corresponds to data secretly held by the selected data access device; retrieving encrypted subject data from the storage medium; and decrypting the encrypted subject data using the data secretly held by the selected data access device as an encryption key to form the subject data wherein the key identification data is formed from the encryption key; and wherein the encryption key is not directly determinable from data stored on the storage medium including the key identification data and the encrypted subject data.
Claim 13
Dependent Claim
14 words
The method of claim 10 wherein the storage medium is a removable storage medium.
Claim 14
Dependent Claim
57 words
The method of claim 10 wherein decrypting comprises: retrieving an encrypted master key from the storage medium; decrypting the encrypted master key using the data secretly held by the selected data access device as an encryption key to form a master key; and decrypting the encrypted subject data using the master key to form the subject data.
Claim 15
Dependent Claim
28 words
The method of claim 10 further comprising: retrieving message verification data from the storage medium; and verifying authenticity of the key identification data using the message verification data.
Claim 16
Dependent Claim
16 words
The method of claim 13 wherein the message verification data is a message authentication code (MAC).
Claim 17
Dependent Claim
13 words
The method of claim 10 wherein the subject data includes digitized audio signals.
Claim 18
Dependent Claim
13 words
The method of claim 15 further comprising: playing back the digitized audio signals.
Claim 19
Dependent Claim
13 words
The method of claim 10 wherein the subject data includes digitized video signals.
Claim 20
Dependent Claim
12 words
The method of claim 17 further comprising: rendering the digitized video signals.
Claim 21
Dependent Claim
12 words
The method of claim 10 wherein the subject data includes computer code.
Claim 22
Dependent Claim
11 words
The method of claim 19 further comprising: executing the computer code.
Claim 23
Independent Claim
95 words
A method for accessing subject data from a storage medium by a selected data access device, the method comprising: receiving key data corresponding to a second data access device from the second data access device; retrieving key identification data from the storage medium; determining that the key identification data corresponds to the key data received from the second data access device; retrieving encrypted subject data from the storage medium; and decrypting the encrypted subject data using the key data received from the second data access device as an encryption key to form the subject data.
Claim 24
Independent Claim
95 words
A method for accessing subject data from a storage medium by a selected data access device, the method comprising: receiving key data corresponding to a second data access device from the second data access device; retrieving key identification data from the storage medium; determining that the key identification data corresponds to the key data received from the second data access device; retrieving encrypted subject data from the storage medium; and decrypting the encrypted subject data using the key data received from the second data access device as an encryption key to form the subject data.
Claim 25
Dependent Claim
14 words
The method of claim 21 wherein the storage medium is a removable storage medium.
Claim 26
Dependent Claim
57 words
The method of claim 21 wherein decrypting comprises: retrieving an encrypted master key from the storage medium; decrypting the encrypted master key using the data secretly held by the selected data access device as an encryption key to form a master key; and decrypting the encrypted subject data using the master key to form the subject data.
Claim 27
Dependent Claim
61 words
The method of claim 21 wherein receiving key data corresponding to a second data access device comprises: sending a request message to the second data access device requesting key data from the second data access device; receiving a reply message from the second data access device which includes encrypted key data; decrypting the encrypted key data to form the key data.
Claim 28
Dependent Claim
43 words
The method of claim 24 wherein receiving key data corresponding to a second data access device further comprises: sending an exchange message to the second data access device where the exchange message includes encrypted key data corresponding to the selected data access device.
Claim 29
Dependent Claim
28 words
The method of claim 24 wherein receiving key data corresponding to a second data access device further comprises: receiving a terminate message from the second data access device.
Claim 30
Dependent Claim
47 words
The method of claim 24 wherein receiving key data corresponding to a second data access device further comprises: preventing storage of the key data within the selected data access device upon a condition in which equivalent key data is already stored within the selected data access device.
Claim 31
Dependent Claim
13 words
The method of claim 24 wherein the request message includes a pseudo-random number.
Claim 32
Dependent Claim
19 words
The method of claim 28 wherein the reply message include the first-mentioned pseudo-random number and a second pseudo-random number.
Claim 33
Dependent Claim
18 words
The method of claim 24 wherein the request message includes a certificate of the selected data access device.
Claim 34
Dependent Claim
25 words
The method of claim 24 wherein the request message conveys a public key of the selected data access device to the second data access device.
Claim 35
Dependent Claim
32 words
The method of claim 31 wherein decrypting the encrypted key data comprises: decrypting the encrypted key data using the private key of the selected data access device to form the key data.
Claim 36
Dependent Claim
79 words
The method of claim 21 wherein receiving key data corresponding to a second data access device comprises: receiving a request message from the second data access device requesting key data from the selected data access device; sending a reply message to the second data access device which includes encrypted key data; receiving an exchange message from the second data access device which includes other encrypted key data; and decrypting the other encrypted key data to form the key data.
Claim 37
Dependent Claim
30 words
The method of claim 21 wherein the encryption key is not directly determinable from data stored on the storage medium including the key identification data and the encrypted subject data.
Claim 38
Dependent Claim
139 words
A computer readable medium useful in association with a computer which includes a processor and a memory, the computer readable medium including computer instructions which are configured to cause the computer to bind subject data to a selected data access device such that the subject data is inaccessible to data access devices other than the selected data access device by: encrypting the subject data to form encrypted subject data using data corresponding to the selected data access device as an encryption key; forming key identification data from the encryption key; and storing the encrypted subject data and the key identification data in a storage medium which is readable by the selected data access device; wherein the encryption key is not directly determinable from data stored on the storage medium including the key identification data and the encrypted subject data.
Claim 39
Dependent Claim
139 words
A computer readable medium useful in association with a computer which includes a processor and a memory, the computer readable medium including computer instructions which are configured to cause the computer to bind subject data to a selected data access device such that the subject data is inaccessible to data access devices other than the selected data access device by: encrypting the subject data to form encrypted subject data using data corresponding to the selected data access device as an encryption key; forming key identification data from the encryption key; and storing the encrypted subject data and the key identification data in a storage medium which is readable by the selected data access device; wherein the encryption key is not directly determinable from data stored on the storage medium including the key identification data and the encrypted subject data.
Claim 40
Dependent Claim
36 words
The computer readable medium of claim 35 wherein encrypting the subject data comprises: encrypting the subject data using a master key; and encrypting the master key with the encryption key to form an encrypted master key.
Claim 41
Dependent Claim
29 words
The computer readable medium of claim 36 wherein storing the encrypted subject data and the key identification data further comprises: storing the encrypted master key in the storage medium.
Claim 42
Dependent Claim
71 words
The computer readable medium of claim 37 wherein the computer instructions are configured to cause the computer to bind subject data to a selected data access device such that the subject data is inaccessible to data access devices other than the selected data access device by also: forming message verification data using the key identification data and the encrypted master key; and storing the message verification data in the storage medium.
Claim 43
Dependent Claim
18 words
The computer readable medium of claim 38 wherein the message verification data is a message authentication code (MAC).
Claim 44
Dependent Claim
66 words
The computer readable medium of claim 35 wherein the computer instructions are configured to cause the computer to bind subject data to a selected data access device such that the subject data is inaccessible to data access devices other than the selected data access device by also: forming message verification data using the key identification data; and storing the message verification data in the storage medium.
Claim 45
Dependent Claim
18 words
The computer readable medium of claim 40 wherein the message verification data is a message authentication code (MAC).
Claim 46
Dependent Claim
15 words
The computer readable medium of claim 35 wherein the subject data includes digitized audio signals.
Claim 47
Dependent Claim
20 words
The computer readable medium of claim 35 wherein the data secretly held by the selected data access device is read-only.
Claim 48
Dependent Claim
142 words
A computer readable medium useful in association with a computer which includes a processor and a memory, the computer readable medium including computer instructions which are configured to cause the computer to access subject data from a storage medium by a selected data access device by: retrieving key identification data from the storage medium; determining that the key identification data corresponds to data secretly held by the selected data access device; retrieving encrypted subject data from the storage medium; and decrypting the encrypted subject data using the data secretly held by the selected data access device as an encryption key to form the subject data; wherein the key identification data is formed from the encryption key; and wherein the encryption key is not directly determinable from data stored on the storage medium including the key identification data and the encrypted subject data.
Claim 49
Dependent Claim
142 words
A computer readable medium useful in association with a computer which includes a processor and a memory, the computer readable medium including computer instructions which are configured to cause the computer to access subject data from a storage medium by a selected data access device by: retrieving key identification data from the storage medium; determining that the key identification data corresponds to data secretly held by the selected data access device; retrieving encrypted subject data from the storage medium; and decrypting the encrypted subject data using the data secretly held by the selected data access device as an encryption key to form the subject data; wherein the key identification data is formed from the encryption key; and wherein the encryption key is not directly determinable from data stored on the storage medium including the key identification data and the encrypted subject data.
Claim 50
Dependent Claim
16 words
The computer readable medium of claim 44 wherein the storage medium is a removable storage medium.
Claim 51
Dependent Claim
59 words
The computer readable medium of claim 44 wherein decrypting comprises: retrieving an encrypted master key from the storage medium; decrypting the encrypted master key using the data secretly held bay the selected data access device as an encryption key to form a master key; and decrypting the encrypted subject data using the master key to from the subject data.
Claim 52
Dependent Claim
54 words
The computer readable medium of claim 44 wherein the computer instructions are configured to cause the computer to access subject data from a storage medium by a selected data access device by also: retrieving message verification data from the storage medium; and verifying authenticity of the key identification data using the message verification data.
Claim 53
Dependent Claim
18 words
The computer readable medium of claim 47 wherein the message verification data is a message authentication code (MAC).
Claim 54
Dependent Claim
15 words
The computer readable medium of claim 44 wherein the subject data includes digitized audio signals.
Claim 55
Dependent Claim
39 words
The computer readable medium of claim 49 wherein the computer instructions are configured to cause the computer to access subject data from a storage medium by a selected data access device by also: playing back the digitized audio signals.
Claim 56
Dependent Claim
15 words
The computer readable medium of claim 44 wherein the subject data includes digitized video signals.
Claim 57
Dependent Claim
38 words
The computer readable medium of claim 51 wherein the computer instructions are configured to cause the computer to access subject data from a storage medium by a selected data access device by also: rendering the digitized video signals.
Claim 58
Dependent Claim
14 words
The computer readable medium of claim 44 wherein the subject data includes computer code.
Claim 59
Dependent Claim
37 words
The computer readable medium of claim 53 wherein the computer instructions are configured to cause the computer to access subject data from a storage medium by a selected data access device by also: executing the computer code.
Claim 60
Dependent Claim
122 words
A computer readable medium useful in association with a computer which includes a processor and a memory, the computer readable medium including computer instructions which are configured to cause the computer to access subject data from a storage medium by a selected data access device by: receiving key data corresponding to a second data access device from the second data access device; retrieving key identification data from the storage medium; determining that the key identification data corresponds to the key data received from the second data access device; retrieving encrypted subject data from the storage medium; and decrypting the encrypted subject data using the key data received from the second data access device as an encryption key to form the subject data.
Claim 61
Dependent Claim
122 words
A computer readable medium useful in association with a computer which includes a processor and a memory, the computer readable medium including computer instructions which are configured to cause the computer to access subject data from a storage medium by a selected data access device by: receiving key data corresponding to a second data access device from the second data access device; retrieving key identification data from the storage medium; determining that the key identification data corresponds to the key data received from the second data access device; retrieving encrypted subject data from the storage medium; and decrypting the encrypted subject data using the key data received from the second data access device as an encryption key to form the subject data.
Claim 62
Dependent Claim
16 words
The computer readable medium of claim 55 wherein the storage medium is a removable storage medium.
Claim 63
Dependent Claim
59 words
The computer readable medium of claim 55 wherein decrypting comprises: retrieving an encrypted master key from the storage medium; decrypting the encrypted master key using the data secretly held by the selected data access device as an encryption key to form a master key; and decrypting the encrypted subject data using the master key to form the subject data.
Claim 64
Dependent Claim
63 words
The computer readable medium of claim 55 wherein receiving key data corresponding to a second data access device comprises: sending a request message to the second data access device requesting key data from the second data access device; receiving a reply message from the second data access device which includes encrypted key data; decrypting the encrypted key data to form the key data.
Claim 65
Dependent Claim
45 words
The computer readable medium of claim 58 wherein receiving key data corresponding to a second data access device further comprises: sending an exchange message to the second data access device where the exchange message includes encrypted key data corresponding to the selected data access device.
Claim 66
Dependent Claim
30 words
The computer readable medium of claim 58 wherein receiving key data corresponding to a second data access device further comprises: receiving a terminate message from the second data access device.
Claim 67
Dependent Claim
49 words
The computer readable medium of claim 58 wherein receiving key data corresponding to a second data access device further comprises: preventing storage of the key data within the selected data access device upon a condition in which equivalent key data is already stored within the selected data access device.
Claim 68
Dependent Claim
15 words
The computer readable medium of claim 58 wherein the request message includes a pseudo-random number.
Claim 69
Dependent Claim
21 words
The computer readable medium of claim 62 wherein the reply message include the first-mentioned pseudo-random number and a second pseudo-random number.
Claim 70
Dependent Claim
20 words
The computer readable medium of claim 58 wherein the request message includes a certificate of the selected data access device.
Claim 71
Dependent Claim
27 words
The computer readable medium of claim 58 wherein the request message conveys a public key of the selected data access device to the second data access device.
Claim 72
Dependent Claim
34 words
The computer readable medium of claim 65 wherein decrypting the encrypted key data comprises: decrypting the encrypted key data using the private key of the selected data access device to form the key data.
Claim 73
Dependent Claim
81 words
The computer readable medium of claim 55 wherein receiving key data corresponding to a second data access device comprises: receiving a request message from the second data access device requesting key data from the selected data access device; sending a reply message to the second data access device which includes encrypted key data; receiving an exchange message from the second data access device which includes other encrypted key data; and decrypting the other encrypted key data to form the key data.
Claim 74
Dependent Claim
32 words
The computer readable medium of claim 55 wherein the encryption key is not directly determinable from data stored on the storage medium including the key identification data and the encrypted subject data.
Claim 75
Dependent Claim
145 words
A computer system comprising: a processor; a memory operatively coupled to the processor; and a binding module (i) which executes in the processor from the memory and (ii) which, when executed by the processor, causes the computer to bind subject data to a selected data access device such that the subject data is inaccessible to data access devices other than the selected data access device by: encrypting the subject data to form encrypted subject data using data corresponding to the selected data access device as an encryption key; forming key identification data from the encryption key; and storing the encrypted subject data and the key identification data in a storage medium which is readable by the selected data access device; wherein the encryption key is not directly determinable from data stored on the storage medium including the key identification data and the encrypted subject data.
Claim 76
Dependent Claim
145 words
A computer system comprising: a processor; a memory operatively coupled to the processor; and a binding module (i) which executes in the processor from the memory and (ii) which, when executed by the processor, causes the computer to bind subject data to a selected data access device such that the subject data is inaccessible to data access devices other than the selected data access device by: encrypting the subject data to form encrypted subject data using data corresponding to the selected data access device as an encryption key; forming key identification data from the encryption key; and storing the encrypted subject data and the key identification data in a storage medium which is readable by the selected data access device; wherein the encryption key is not directly determinable from data stored on the storage medium including the key identification data and the encrypted subject data.
Claim 77
Dependent Claim
35 words
The computer system of claim 69 wherein encrypting the subject data comprises: encrypting the subject data using a master key; and encrypting the master key with the encryption key to form an encrypted master key.
Claim 78
Dependent Claim
28 words
The computer system of claim 70 wherein storing the encrypted subject data and the key identification data further comprises: storing the encrypted master key in the storage medium.
Claim 79
Dependent Claim
72 words
The computer system of claim 71 wherein the binding module, when executed by the processor, causes the computer to bind subject data to a selected data access device such that the subject data is inaccessible to data access devices other than the selected data access device by also: forming message verification data using the key identification data and the encrypted master key; and storing the message verification data in the storage medium.
Claim 80
Dependent Claim
17 words
The computer system of claim 72 wherein the message verification data is a message authentication code (MAC).
Claim 81
Dependent Claim
67 words
The computer system of claim 69 wherein the binding module, when executed by the processor, causes the computer to bind subject data to a selected data access device such that the subject data is inaccessible to data access devices other than the selected data access device by also: forming message verification data using the key identification data; and storing the message verification data in the storage medium.
Claim 82
Dependent Claim
17 words
The computer system of claim 74 wherein the message verification data is a message authentication code (MAC).
Claim 83
Dependent Claim
14 words
The computer system of claim 69 wherein the subject data includes digitized audio signals.
Claim 84
Dependent Claim
18 words
The computer system of claim 69 wherein the data secretly held by selected data access device is read-only.
Claim 85
Dependent Claim
149 words
A computer system comprising: a processor; a memory operatively coupled to the processor; and a data access module (i) which executes in the processor from the memory and (ii) which, when executed by the processor, causes the computer to access subject data from a storage medium by a selected data access device by: retrieving key identification data from the storage medium; determining that the key identification data corresponds to data secretly held by the selected data access device; retrieving encrypted subject data from the storage medium; and decrypting the encrypted subject data using the data secretly held by the selected data access device as an encryption key to form the subject data; wherein the key identification data is formed from the encryption key; and wherein the encryption key is not directly determinable from data stored on the storage medium including the key identification data and the encrypted subject data.
Claim 86
Dependent Claim
149 words
A computer system comprising: a processor; a memory operatively coupled to the processor; and a data access module (i) which executes in the processor from the memory and (ii) which, when executed by the processor, causes the computer to access subject data from a storage medium by a selected data access device by: retrieving key identification data from the storage medium; determining that the key identification data corresponds to data secretly held by the selected data access device; retrieving encrypted subject data from the storage medium; and decrypting the encrypted subject data using the data secretly held by the selected data access device as an encryption key to form the subject data; wherein the key identification data is formed from the encryption key; and wherein the encryption key is not directly determinable from data stored on the storage medium including the key identification data and the encrypted subject data.
Claim 87
Dependent Claim
15 words
The computer system of claim 78 wherein the storage medium is a removable storage medium.
Claim 88
Dependent Claim
58 words
The computer system of claim 78 wherein decryption comprises: retrieving an encrypted master key from the storage medium; decrypting the encrypted master key using the data secretly held by the selected data access device as an encryption key to form a master key; and decrypting the encrypted subject data using the master key to form the subject data.
Claim 89
Dependent Claim
56 words
The computer system of claim 78 wherein the data access module, when executed by the processor, causes the computer to access subject data from a storage medium by a selected data access device by also: retrieving message verification data from the storage medium; and verifying authenticity of the key identification data using the message verification data.
Claim 90
Dependent Claim
17 words
The computer system of claim 81 wherein the message verification data is a message authentication code (MAC).
Claim 91
Dependent Claim
14 words
The computer system of claim 78 wherein the subject data includes digitized audio signals.
Claim 92
Dependent Claim
41 words
The computer system of claim 83 wherein the data access module, when executed by the processor, causes the computer to access subject data from a storage medium by a selected data access device by also: playing back the digitized audio signals.
Claim 93
Dependent Claim
14 words
The computer system of claim 78 wherein the subject data includes digitized video signals.
Claim 94
Dependent Claim
40 words
The computer system of claim 85 wherein the data access module, when executed by the processor, causes the computer to access subject data from a storage medium by a selected data access device by also: rendering the digitized video signals.
Claim 95
Dependent Claim
13 words
The computer system of claim 78 wherein the subject data includes computer code.
Claim 96
Dependent Claim
39 words
The computer system of claim 87 wherein the data access module, when executed by the processor, causes the computer to access subject data from a storage medium by a selected data access device by also: executing the computer code.
Claim 97
Dependent Claim
129 words
A computer system comprising: a processor; a memory operatively coupled to the processor; and a data access module (i) which executes in the processor from the memory and (ii) which, when executed by the processor, causes the computer to access subject data from a storage medium by a selected data access device by: receiving key data corresponding to a second data access device from the second data access device; retrieving key identification data from the storage medium; determining that the key identification data corresponds to the key data received from the second data access device, retrieving encrypted subject data from the storage medium; and decrypting the encrypted subject data using the key data received from the second data access device as an encryption key to form the subject data.
Claim 98
Dependent Claim
129 words
A computer system comprising: a processor; a memory operatively coupled to the processor; and a data access module (i) which executes in the processor from the memory and (ii) which, when executed by the processor, causes the computer to access subject data from a storage medium by a selected data access device by: receiving key data corresponding to a second data access device from the second data access device; retrieving key identification data from the storage medium; determining that the key identification data corresponds to the key data received from the second data access device, retrieving encrypted subject data from the storage medium; and decrypting the encrypted subject data using the key data received from the second data access device as an encryption key to form the subject data.
Claim 99
Dependent Claim
15 words
The computer system of claim 89 wherein the storage medium is a removable storage medium.
Claim 100
Dependent Claim
58 words
The computer system of claim 89 wherein decrypting comprises retrieving an encrypted master key from the storage medium; decrypting the encrypted master key using the data secretly held by the selected data access device as an encryption key to form a master key; and decrypting the encrypted subject data using the master key to form the subject data.
Claim 101
Dependent Claim
62 words
The computer system of claim 89 wherein receiving key data corresponding to a second data access device comprises: sending a request message to the second data access device requesting key data from the second data access device; receiving a reply message from the second data access device which includes encrypted key data; decrypting the encrypted key data to form the key data.
Claim 102
Dependent Claim
44 words
The computer system of claim 92 wherein receiving key data corresponding to a second data access device further comprises: sending an exchange massage to the second data access device where the exchange message includes encrypted key data corresponding to the selected data access device.
Claim 103
Dependent Claim
29 words
The computer system of claim 92 wherein receiving key data corresponding to a second data access device further comprises: receiving a terminate message from the second data access device.
Claim 104
Dependent Claim
48 words
The computer system of claim 92 wherein receiving key data corresponding to a second data access device further comprises: preventing storage of the key data within the selected data access device upon a condition in which equivalent key data is already stored within the selected data access device.
Claim 105
Dependent Claim
14 words
The computer system of claim 92 wherein the request message includes a pseudo-random number.
Claim 106
Dependent Claim
20 words
The computer system of claim 96 wherein the reply message include the first-mentioned pseudo-random number and a second pseudo-random number.
Claim 107
Dependent Claim
19 words
The computer system of claim 92 wherein the request message includes a certificate of the selected data access device.
Claim 108
Dependent Claim
26 words
The computer system of claim 92 wherein the request message conveys a public key of the selected data access device to the second data access device.
Claim 109
Dependent Claim
33 words
The computer system of claim 99 wherein decrypting the encrypted key data comprises: decrypting the encrypted key data using the private key of the selected data access device to form the key data.
Claim 110
Dependent Claim
80 words
The computer system of claim 89 wherein receiving key data corresponding to a second data access device comprises: receiving a request message from the second data access device requesting key data from the selected data access device; sending a reply message to the second data access device which includes encrypted key data; receiving an exchange message from the second data access device which includes other encrypted key data; and decrypting the other encrypted key data to form the key data.
Claim 111
Dependent Claim
31 words
The computer system of claim 89 wherein the encryption key is not directly determinable from data stored on the storage medium including the key identification data and the encrypted subject data.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2005-04-01 | 2005-10-01 | 2006-04-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2009-04-01 | 2009-10-01 | 2010-04-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2013-04-01 | 2013-10-01 | 2014-04-02 | $7700.00 | Window Closed / Lapsed |