Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
108 words
A secure timekeeping facility for use in a computer system that includes a central processing unit and electronic storage located in a physically secure package, comprising: a time-of-day (TOD) clock including a time clock and a date calendar; an authenticated-time indicator for storing a value indicating whether the TOD clock contains an authenticated time and date; an accuracy-duration register for storing a value indicating a time duration for which the TOD clock is considered accurate; an input for receiving any of time, date, and accuracy duration values; and an output for providing unencrypted time and date values from the TOD clock and a value from the authenticated-time indicator.
Claim 2
Dependent Claim
108 words
A secure timekeeping facility for use in a computer system that includes a central processing unit and electronic storage located in a physically secure package, comprising: a time-of-day (TOD) clock including a time clock and a date calendar; an authenticated-time indicator for storing a value indicating whether the TOD clock contains an authenticated time and date; an accuracy-duration register for storing a value indicating a time duration for which the TOD clock is considered accurate; an input for receiving any of time, date, and accuracy duration values; and an output for providing unencrypted time and date values from the TOD clock and a value from the authenticated-time indicator.
Claim 3
Dependent Claim
66 words
The secure timekeeping facility as recited in claim 1, wherein the accuracy duration register contains a time value, and the authenticated-time indicator is set to TRUE responsive to the combination of setting the TOD clock using encrypted values, setting the accuracy duration register using an encrypted value, and the accuracy duration register containing a value which is chronologically greater than the value of the TOD clock.
Claim 4
Dependent Claim
54 words
The secure timekeeping facility as recited in claim 2, wherein the authenticated time indicator is set to FALSE for any of system initialization, low operating voltage condition, setting of the TOD clock using unencrypted values, and the accuracy duration register containing a value which is chronologically less than the value of the TOD clock.
Claim 5
Dependent Claim
90 words
The secure timekeeping facility as recited in claim 1, further comprising: a time facility setting means for setting the values of the TOD clock and the accuracy-duration register based on the received time, date, and accuracy duration values, and for setting the authenticated time indicator to FALSE if the received time, date, and accuracy duration values are unencrypted, TRUE if the received time, date, and accuracy duration values are encrypted and the value set in the accuracy duration register is chronologically greater than the value set in the TOD clock.
Claim 6
Dependent Claim
74 words
The secure timekeeping facility as recited in claim 4, wherein the secure timekeeping facility further comprises a calibration adjustment register for storing a value indicating a time interval at which the TOD clock is to receive a calibration adjustment, wherein the input further comprises means for receiving a calibration adjustment value, and wherein the time facility setting means further comprises means for setting the calibration adjustment register based on the received calibration adjustment value.
Claim 7
Dependent Claim
49 words
The secure timekeeping facility as recited in claim 5, further comprising a TOD clock calibrator, operatively connected to the TOD clock and the calibration adjustment register, for applying a calibration adjustment to the TOD clock each time the TOD clock increments to the value of the calibration adjustment register.
Claim 8
Dependent Claim
85 words
The secure timekeeping facility as recited in claim 6, wherein the value of the calibration adjustment register may indicate any of increment, skip, and no-adjust, and wherein for a calibration adjustment value indicating increment the calibration adjustment applied to the TOD clock is a single additive increment, for a calibration adjustment value indicating skip the calibration adjustment applied to the TOD clock is a single increment skip. for a calibration adjustment value indicating no-adjust the calibration adjustment applied to the TOD clock is zero increments.
Claim 9
Dependent Claim
31 words
The secure timekeeping facility as recited in claim 7, wherein a positive calibration adjustment value indicates increment, a negative calibration adjustment value indicates skip, and zero calibration adjustment, value indicates no-adjust.
Claim 10
Dependent Claim
36 words
The secure timekeeping facility as recited in claim 7, further comprising: a time facility reading means for reading the unencrypted values of the TOD clock, the authenticated-time indicator, the accuracy-duration register, and the calibration adjustment register.
Claim 11
Dependent Claim
70 words
The secure timekeeping facility as recited in claim 9, wherein the value of the calibration adjustment register is a function of an amount of drift accumulated in the TOD clock since the last setting of the TOD clock, and wherein the value of the accuracy-duration register is based on a comparison between the amount of drift and previously measured amounts of drift corresponding to previous settings of the TOD clock.
Claim 12
Dependent Claim
72 words
The secure timekeeping facility as recited in claim 4, further comprising secure-time request means for requesting from a time server any of current time, date, and accuracy-duration values, and wherein a request initiated by the secure-time request means includes any of the present value of the TOD clock, the present value of the accuracy duration register, the present value of the calibration adjustment register, and the present value of the authenticated-time indicator.