Nippon Steel Corporation

Ntt Communications Corporation

Nippon Steel Nisshin Co., Ltd.

Atsuo Shimizu

Hiromasa Shoji

Koji Akioka

Atsushi Okada

Ikumi Tokuda

Yoshikatsu Nishida

Yoshiharu Iwamizu

This surface-treated steel sheet includes: a steel sheet; a Zn-based plating layer formed on the steel sheet; and a coating formed on the Zn-based plating layer, in which a Si concentration, a P concentration, a F concentration, a V concentration, a Zr concentration, a Zn concentration, and an Al concentration of the coating are, by mass %, Si: 10.00% to 25.00%, P: 0.01% to 5.00%, F: 0.01% to 2.00%, V: 0.01% to 4.00%, Zr: 0.01% to 3.00%, Zn: 0% to 3.00%, and Al: 0% to 3.00%, in a narrow spectrum of 5i2p obtained by performing XP S analysis on a surface of the coating, a ratio of an integrated intensity of a peak having a local, maximum value, at 103.37±0.25 eV to an integrated intensity of a peak having a local maximum value at 102.26±0.25 eV is 0.04 or more and 0.25 or less.

Surface-treated steel sheet

A surface-treated steel sheet includes: a base steel sheet; a plated layer formed on the base steel sheet and containing 50 mass % or more of Zn and 0.3 mass % or more of Mg; and a chemical conversion coating formed on the plated layer. The chemical conversion coating contains a silicon compound, P and F, and Mg, an average Si concentration of the chemical conversion coating is 10 mass % or more, the chemical conversion coating includes an F—Mg concentrated layer having an Mg concentration of 1.50 mass % or more and 40.00 mass % or less and an F concentration of 0.50 mass % or more and 5.00 mass % or less in a region in contact with an interface between the chemical conversion coating and the plated layer, a thickness of the F—Mg concentrated layer is 1.0 nm or more, and an average Mg concentration is less than 0.50 mass % and an average F concentration is less than 0.50 mass % in a region of the chemical conversion coating excluding the F—Mg concentrated layer.

A communication apparatus for use in a communication system including a call control apparatus and a key information distribution apparatus is provided. The communication apparatus includes a key generation means configured to, when media communication is performed between the communication apparatus and another communication apparatus, request the key information distribution apparatus to provide common key generation information for generating a first common key, a call control means configured to establish a call connection between the communication apparatus and said another communication apparatus by transmitting a call connection request to the call control apparatus, and a communication means configured to transmit and receive an encrypted media packet by using a second common key, wherein the key generation means generates the first common key by using the common key generation information received from the key information distribution apparatus, and after the first common key is generated, the communication means transmits and receives an encrypted media packet by using the first common key.

Communication apparatus, communication method, and program

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Tokyo, Japan

Atsuo Shimizu