Fr Matthew Charlesworth, SJ
Fr Matthew Charlesworth, SJ
https://sj.mcharlesworth.fr/

Verify my Email Signature

If you received a signed email from matthew@mcharlesworth.fr and your email application says that the certificate is not trusted, that is expected until you establish trust manually.

Certificate details

Name: Fr Matthew Charlesworth, SJ
Email: matthew@mcharlesworth.fr
Website: https://sj.mcharlesworth.fr/

Valid from: 2026-04-06 until: 2036-04-03

SHA-256 fingerprint

E8 59 48 95 DF 46 E1 81 5C 4B C3 5E CF CD 57 3A 8B F6 7A 74 D2 ED 7F 19 D2 61 A9 43 91 7D 8F B4

SHA-1 fingerprint

98 6D B8 23 24 66 5F C7 8C 2F 0F 0D 47 B9 A0 2C F1 75 EA 53

Public certificate

Download the public certificate

Notes

Used for personal signed email.

Authority

This certificate is issued under my private email signing authority. You can review that authority here: Email Signing Authority.

Revocation

If this certificate is ever replaced or compromised, I will publish an updated certificate and fingerprint on this website.

Any previous certificate should then be considered no longer valid.

How to trust it

Trusting a certificate is usually a one-time manual step. Once trusted, future signed emails from me should verify normally, provided I continue using the same certificate authority and the relevant certificate remains valid.

Apple Mail on macOS

  1. Open the signed email.
  2. Click the signature or certificate icon.
  3. View the certificate details.
  4. Confirm that the email address and fingerprint match this page.
  5. Add the certificate to Keychain if prompted.
  6. In Keychain Access, locate the certificate and set it to trust for email use if needed.

iPhone or iPad Mail

  1. Open the signed message.
  2. Tap the signature indicator.
  3. View the certificate.
  4. Confirm that the email address and fingerprint match this page.
  5. Accept or trust the certificate if your device gives you that option.

Thunderbird

  1. Open the signed email.
  2. Click the signature icon.
  3. View the certificate.
  4. Confirm that the email address and fingerprint match this page.
  5. Import or trust the certificate in Thunderbird’s certificate manager if needed.

Outlook on Windows

  1. Open the signed message.
  2. Open the signature details.
  3. View the certificate.
  4. Confirm that the email address and fingerprint match this page.
  5. Install it into the appropriate certificate store, usually Trusted People, if you want future signed messages from me to verify without warnings.

A note on security

Please do not trust the certificate merely because an email asks you to do so. Always compare the certificate fingerprint in your email program with the fingerprint published on this page.

If the fingerprint does not match exactly, do not trust the certificate.

Why I use this system

I use my own certificate authority to sign email cryptographically. This allows me to rotate individual email certificates when necessary while keeping a stable chain of trust.

If you are unsure

If you are uncertain whether to trust a certificate, please contact me through a known and trusted channel before proceeding.

Contact

If you are uncertain, please contact me through a known channel before trusting the certificate.

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