Opera Help

Security certificates

Security certificates are used to verify that a website is secure to use. Most of the time certificates are fully valid and you can proceed safely with your business. If there is something questionable about a certificate, a warning dialog will be displayed, as explained in the Certificate warnings topic below.

Certificate warnings

If there is something questionable about a certificate, a warning dialog will be displayed. You may choose to proceed, but full security cannot be guaranteed at this point.

Server certificate expired
Certificates like credit cards have an expiry date, and must be renewed on a regular basis by the people maintaining the site.
Accepting an expired certificate does not necessarily reduce security, however take into consideration the site you are visiting and how long since the certificate expired.
Wrong certificate name
A certificate is issued by an authority for a single site to use, and sites cannot borrow certificates from each other as this invalidates the whole concept of certificates.
Accepting a certificate belonging to another site is not recommended.
Certificate signer not found
Certificates are signed by an authority. For example, the secure version of the University of Oslo website is authorized by the Thawte organization.
If the signer of a certificate is not found in your list of authorities, you should not accept the certificate unless you have a confident relation with the website.
Some certificates are self-signed, that is, signed by the person or organization running the site, and not an authority. Trusting a self-signed certificate from, for example, your employer can be considered as safe.
If you know that the signer can be trusted, and you want all sites using this signer to be considered as safe, install the certificate to add the signer to your regular list of authorities.

Tip: To see your list of authorities, see Manage certificates below.

Manage certificates

To see an overview of your installed certificates, go to Opera > Preferences > Advanced > Security and select Manage certificates.

Client certificates identify you during transactions with secure websites
Certificate Authorities certify the identity of websites
Intermediate Certificate Authorities certify the identity of websites
You have approved these certificates, which have security issues
You have rejected these certificates, which have security issues

Set a master password

Client certificates, sometimes called personal certificates, are given to you by banks and other secure websites in order to identify you. Since the client certificates stored on your computer are meant to certify your identity, Opera requires you to protect them by setting a master password.

Opera will ask you to set a master password the first time that you install a client certificate. You should select a password that is impossible to guess, and keep it secret. When you want to use your client certificates, Opera will ask you to enter the master password.

To later change the master password, or to set a master password even in the absence of any client certificates, press the button marked "Set Master Password". The master password can be used to protect not just your client certificates, but also your saved passwords.

Ask for password

Once the master password is set, you may adjust the interval at which it is checked. By default, the interval is set to "Every time needed", meaning every time that you need a client certificate, or every time you need a stored password, if you have checked "Use master password to protect saved passwords".

Related topics

See also: Guide to security and privacy in Opera