The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.

The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.

Date of Patent:
Oct. 23, 2018

Filed:

May. 19, 2016
Applicant:

Renesas Electronics Corporation, Koutou-ku, Tokyo, JP;

Inventor:

Daisuke Oshida, Tokyo, JP;

Assignee:
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H04W 76/02 (2009.01); H04L 29/06 (2006.01); H04W 12/04 (2009.01); H04W 12/10 (2009.01); H04W 72/04 (2009.01); H04L 9/32 (2006.01); H04W 76/16 (2018.01); H04W 4/70 (2018.01); H04W 12/12 (2009.01); H04L 29/08 (2006.01); H04W 4/04 (2009.01); H04W 4/02 (2018.01);
U.S. Cl.
CPC ...
H04W 76/026 (2013.01); H04L 9/3268 (2013.01); H04L 9/3297 (2013.01); H04L 63/0428 (2013.01); H04L 63/068 (2013.01); H04L 63/123 (2013.01); H04W 4/70 (2018.02); H04W 12/04 (2013.01); H04W 12/10 (2013.01); H04W 72/0446 (2013.01); H04W 76/16 (2018.02); H04L 63/0823 (2013.01); H04L 67/12 (2013.01); H04L 2209/84 (2013.01); H04L 2463/121 (2013.01); H04W 4/02 (2013.01); H04W 4/046 (2013.01); H04W 12/12 (2013.01);
Abstract

The communication terminal includes a communication interface for acquiring external time information from outside and a non-volatile memory and operates as described below. The communication terminal periodically acquires external time information, encrypts the internal time information calibrated based on the acquired external time information, and thereafter writes the encrypted internal time information into the non-volatile memory. In an initialization sequence after power-on of the communication terminal, the communication terminal reads and decrypts internal time information that is lastly written to the non-volatile memory before the power-on, newly acquires external time information, and verifies validity of the acquired external time information by comparing the acquired external time information with the read internal time information.


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