Secure seed provisioning
View Patent ↗A technique is utilized in the configuration and seeding of security tokens at third party facilities, particularly at facilities of a configuration agent, such that a token can be configured without the configuration agent having security-defeating knowledge about the token. Such a technique allows a third party to provision a token with a seed, but in such a way that the third party will not know, or be able to construct, the seed after the seed provisioning process is complete. The seed may include, by way of example, a symmetric key or other secret shared by two or more entities. In some arrangements, a method is used for secure seed provisioning. Data is derived from inherent randomness in a token or other authentication device. Based on the data, the token or other authentication device is provisioned with a seed.
1. A method for use in secure seed provisioning, the method comprising the steps of:
deriving, by an authentication device, data from an inherent source of randomness in the authentication device;
based on the data, provisioning, by the authentication device, the authentication device with a seed;
preventing, by the authentication device, direct external exposure of the seed during the lifetime of the authentication device; and
receiving, by the authentication device and from a programming station, a configuration command to provision the authentication device with the seed, the authentication device being provisioned with the seed in response to the configuration command;
wherein deriving the data from an inherent source of randomness in the authentication device includes:
generating, by a processor of the authentication device, the data based on a counter value which represents an amount of time between (i) when a battery of the authentication device is connected to the processor and (ii) when the configuration command is received from the programming station.
2. The method of claim 1 , wherein the seed comprises a symmetric key.
3. The method of claim 1 , wherein the inherent source of randomness is based on a powerup characteristic of the authentication device.
4. The method of claim 1 , wherein the inherent source of randomness is based on an electronic component characteristic of the authentication device.
5. The method of claim 1 , wherein the inherent source of randomness is based on an amount of time between unsynchronized events in the authentication device.
6. The method of claim 1 , further comprising:
starting to increment a counter when power is applied to the authentication device,
wherein the data is based on a value of the counter.
7. The method of claim 1 , further comprising:
further deriving the data from a source of randomness external to the authentication device.
8. The method of claim 1 , further comprising:
outputting an intermediate level value to a recipient, the intermediate level value being required for the recipient to calculate the seed.
9. The method of claim 1 , further comprising:
deriving a value from the inherent source of randomness; and
outputting the value to a recipient, the value being required for the recipient to calculate the seed.
10. The method of claim 1 , further comprising:
outputting a first value to a first recipient, the first value alone being insufficient to allow calculation of the seed; and
at the first recipient, calculating the seed from the first value and a second value already available to the first recipient, the second value being unavailable to a second recipient.
11. The method of claim 1 , further comprising:
deriving the seed from a unique value provided in the authentication device.
12. The method of claim 1 , further comprising:
using the inherent source of randomness to affect a value of a counter in the authentication device.
13. The method of claim 1 , further comprising:
avoiding resetting the value of a counter in the authentication device to zero when the authentication device is reset.
14. The method of claim 1 , further comprising:
deriving the seed from a source of randomness that is external to the authentication device, the source of randomness being unpredictable and hardware based.
15. The method of claim 1 , further comprising:
deriving the seed using encryption.
16. The method of claim 1 , further comprising:
deriving the seed from a unique value programmed into the authentication device at the time of chip fabrication.
17. The method of claim 1 , further comprising:
controlling access to values such that only one or more authorized entities outside the authentication device have sufficient information to calculate the seed.
18. The method of claim 1 , further comprising:
deriving the seed based on a mapping between a chip serial number and a unique value programmed into the authentication device at the time of chip fabrication.
19. The method of claim 1 , further comprising:
deriving the seed based on a mapping between a serial number of the authentication device and a value based on an external source of randomness.
20. A method for use in secure seed provisioning, the method comprising the steps of:
deriving, by a first authentication device, data from a secret number embedded in multiple authentication devices including the first authentication device, and from a unique number embedded in the first authentication device only;
based on the data, provisioning, by the first authentication device, the first authentication device with a seed;
preventing, by the first authentication device, direct external exposure of the seed from the first authentication device during the lifetime of the first authentication device; and
receiving, by the first authentication device and from a programming station, a configuration command to provision the first authentication device with the seed, the authentication device being provisioned with the seed in response to the configuration command;
wherein deriving the data from the secret number embedded in the multiple authentication devices and from a unique number embedded in the first authentication device only includes:
generating, by a processor of the first authentication device, the data based on a counter value which represents an amount of time between (i) when a battery of the first authentication device is connected to the processor and (ii) when the configuration command is received from the programming station.
21. A method for use in secure seed provisioning, the method comprising the steps of:
deriving, by an authentication device, a first number from an internal source of randomness;
receiving, by the authentication device, a second number based on an external source of randomness;
receiving, by the authentication device, a serial number;
internally retrieving, by the authentication device, a non-unique secret key;
deriving, by the authentication device, a third number from the first number, serial number, and the non-unique secret key;
externally exposing the third number while preventing direct external exposure of the seed from the authentication device during the lifetime of the authentication device; and
deriving a key from the second and third numbers;
wherein deriving the first number from the internal source of randomness includes:
generating, by a processor of the authentication device, the first number based on a counter value which represents an amount of time between (i) when a battery of the authentication device is connected to the processor and (ii) when the second number is received.
22. The method of claim 21 , wherein the authentication device includes a random number generator; and wherein generating the data includes:
providing the data based on both the counter value and a random number supplied by the random number generator, the counter value and the random number being different from each other, the programming station being prevented from ever reading the seed provisioned to the authentication device which is based on the data based on both the counter value and the random number.