Update of Root Certificate for SFC-CNS Wireless LAN Service (Jan 15)
(Published: 2026/01/15)
(Updated: 2026/01/15)
(Updated: 2026/01/19)
(Updated: 2026/01/19)
(Updated: 2026/01/23)
The root certificate for the SFC-CNS wireless LAN connection service will be updated as described below.
Due to a technical issue encountered during the root certificate update originally scheduled for today, the process will be rescheduled. We apologize for any inconvenience caused.
The updated schedule for the root certificate migration is Monday, January 19, from 18:00 to 18:30.
The root certificate update has been successfully completed.
Currently, we have confirmed an issue in which newly issued personal certificates cannot be used to connect to the wireless LAN (CNS) on iOS devices such as iPhones and iPads.
If you plan to update your personal certificate on an iOS device, please perform the update on or after Saturday, January 24, 2026. We sincerely apologize for any inconvenience this may cause and appreciate your understanding.
Date/Time: Monday, January 19, 2026, 18:00 – 18:30
Impact: Users accessing the SFC-CNS wireless environment via personal certificate authentication (EAP-TLS, SSID: CNS)
Specifics: (See below)
| Certificate Authority Chains | ||
|---|---|---|
| [Current] Until 19 January 2026, 18:00 p.m. |
[New] After 19 January 2026, 18:30 p.m. |
|
| Root CA (fingerprint: SHA1) |
KEIO SFC Root CA
G2 (FB:90:09:D1:F6:45:EE:9B:B8:21:8A:09:E3:3F:B0:99:00:58:0E:63) |
KEIO SFC Root CA
G3 (40:D8:21:FE:1D:13:AB:73:C1:5E:90:32:85:8C:D1:DF:27:EC:92:DE) |
| Intermediate CA (fingerprint: SHA1) |
KEIO SFC Intermediate CA
G2 (3D:11:E9:BD:5D:F0:B5:7F:00:14:83:5D:43:C0:F0:22:E0:F6:B3:E4) |
KEIO SFC Intermediate CA
G3 (60:A3:54:8E:FF:99:4C:E4:87:1B:AC:58:9B:66:F7:19:36:FB:60:01) |
| Personal Cert | {Personal CNS Email Address} | {Personal CNS Email Address} |
Due to the root certificate update, currently used personal certificates will no longer be valid starting January 24, 2026.
Users utilizing personal certificate authentication (EAP-TLS, SSID: CNS) must re-issue their personal certificate and install it on their devices by January 23, 2026.
If you are using an iOS device, please perform the above procedure on or after Saturday, January 24, 2026, as indicated in the red text above.
2026/1/23 18:15 - 18:45: Maintenance will be conducted to update the wireless LAN authentication server certificate.
As a result, connection to the wireless LAN (SSID: CNS) using old personal certificates will no longer be possible.
If you have not yet reissued your personal certificate, please reissue it and install it on your device.
Please refer to the following pages for instructions on how to update your personal certificate:
-
Windows 11, macOS, Android
https://secure.itc.keio.ac.jp/c/a/sfc/en/network_information_wireless_802_1x_renew.html
We have confirmed an issue where personal certificates cannot be installed on macOS 14 (macOS Sonoma).
Users on macOS 14 (Sonoma) are requested to update to macOS 15 (macOS Sequoia) before proceeding.
-
iOS devices (iPhone, iPad)
https://secure.itc.keio.ac.jp/c/a/sfc/en/network_information_wireless_802_1x_install_ios.html
Thank you for your understanding and cooperation.
Last-Modified: January 23, 2026
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