Security method and apparatus to prevent replay of external memory data to integrated circuits having only one-time programmable non-volatile memory

Patent metadata

Field	Value
Publication number	US-2016140357-A1
Application number	US-201514941991-A
Country	US
Kind code	A1
Filing date	Nov 16, 2015
Priority date	Nov 18, 2014
Publication date	May 19, 2016
Grant date	—

Abstract

A method for generating a secure nonce using a one-time programmable (OTP) memory within an integrated circuit to provide persistence, the method including randomly selecting k currently-unprogrammed bits in the OTP memory, creating a data set using data derived from current contents of the OTP memory altered by changing the states of the k currently-unprogrammed bits of the OTP memory, and employing as the secure nonce the data set or data derived from the data set. The selected k bits are programmed in the OTP memory.

First claim

The invention claimed is:

1 . A method for generating a secure nonce using a one-time programmable (OTP) memory within an integrated circuit, the method comprising:
randomly selecting k currently-unprogrammed bits in the OTP memory; creating a data set using data derived from current contents of the OTP memory altered by changing the states of the k currently-unprogrammed bits of the OTP memory; and generating the secure nonce from the data set or data derived from the data set.

2 . The method of claim 1 further comprising programming the k currently-unprogrammed bits in the OTP memory.

3 . The method of claim 1 , wherein generating the secure nonce from the data set or data derived from the data set comprises generating the secure nonce from the data set or data derived from the data set and also incorporating a secret value.

4 . The method of claim 3 , further comprising:
computing a physically unclonable function associated with the secure integrated circuit; and incorporating the physically unclonable function in the secret value.

5 . A method for securely writing data from a secure integrated circuit to an external device, the method comprising:
reading current contents of the OTP memory; randomly selecting k currently-unprogrammed bits in the OTP memory; creating a data set using data derived from the current contents of the OTP memory altered by changing the states of the k currently-unprogrammed bits of the OTP memory; programming the k currently-unprogrammed bits of the OTP memory; employing as a secure nonce the data set or data derived from the data set; preparing data to write to the external device; computing a message authentication code from the secure nonce and the data to be written to the external device; and writing the data and the message authentication code to the external device.

6 . A method for authenticating data read into a secure integrated circuit from an external device, the data associated with a message authentication code generated from data written to the external device and from a nonce associated with a current state of a one-time programmable (OTP) memory in the secure integrated circuit, the method comprising:
reading the current state of the OTP memory in the secure integrated circuit; computing a current nonce from the contents of the OTP memory; reading the data and a message authentication code from the external device; computing a correct message authentication code from the received data and the current nonce; comparing the correct message authentication code with the message authentication code received with the data; consuming the data if the correct message authentication code is the same as the message authentication code received with the data; and discarding the data if the correct message authentication code is not the same as the message authentication code received with the data.

7 . The method of claim 6 wherein reading the data and the message authentication code from the external device comprises reading the data and the message authentication code from an external memory device.

8 . The method of claim 7 further comprising:
imposing penalties if the correct message authentication code is not the same as the message authentication code received with the data.

9 . An integrated circuit comprising:
a controller including a central processing unit, a non-volatile storage memory coupled to the central processing unit, and a random bit generator coupled to the central processing unit; a one-time-programmable memory (OTP) coupled to the controller; an external memory interface coupled to the controller; wherein the controller is configured to:
cause the random bit generator to randomly select k currently-unprogrammed bits in the OTP memory;
create a data set using data derived from current contents of the OTP memory altered by changing the states of the k currently-unprogrammed bits of the OTP memory; and
generate a secure nonce from the data set or data derived from the data set.

10 . The integrated circuit of claim 9 wherein the controller is further configured to program the k currently-unprogrammed bits of the OTP memory.

11 . The integrated circuit of claim 9 , further comprising a physically unclonable function and wherein the controller is further configured to employ the physically unclonable function in generating the secure nonce.

Assignees

• Microsemi Soc Corp

Inventors

• Newell G Richard

Classifications

• G06F21/79 Primary

  in semiconductor storage media, e.g. directly-addressable memories · CPC title

• G06F3/0679 Primary

  Non-volatile semiconductor memory device, e.g. flash memory, one time programmable memory [OTP] · CPC title

• G06F3/0629

  Configuration or reconfiguration of storage systems · CPC title

• G06F21/31

  User authentication · CPC title

• G06F21/6218 Primary

  to a system of files or objects, e.g. local or distributed file system or database · CPC title