SDSTool (Simple Digital Signature Tool) is an open-source program for digital signatures that runs in your browser. It can be used for generating and managing key pairs, signing plain text and JSON sign requests as well as verifying signatures. Check out its repository for more info.

Digital signatures enable you to create identities that can be used independently of a third party. Consider a forum where you are required to create an account. Think of that account as an identity of yours. You need to log in whenever you want to post something under that identity. The forum is the third party required to cooperate in order for you to be able to use it.

If your account is banned or the forum ceases to operate, you lose that identity. Moreover, anyone with access to the forum's database can manipulate your posts or write posts in your name. It is also not so easy to establish a single identity across different websites since each one usually has its own account system.

Identities based on digital signatures don't have these problems. Such an identity consists of a public and a private key, which together are called a key pair. The public key is like the username of an account and the private key like the password. Unlike username and password which can be chosen independently, a key pair must be generated by a special algorithm. To post something using a key pair as identity, you sign it. Others can verify the signed post to confirm that it has been made by you. No third party is required.

You can sign your posts before submitting them to a platform. If a platform disables your account, you can still post under that identity anywhere else via your key pair. Additionally, you obtain an identity that can be recognized across platforms.

You can share your public key with your friends so that even if you contact them from an unknown address, they can verify that the message is from you.

Click on the alias that you want to change in the table and it becomes editable. Press enter or focus another element to save the change.

Go to the Settings tab and check that Auto-save and load database is enabled. After setting a password your database will be automatically saved in your browser whenever you modify it. When you open this site you will be prompted for a password to load the database from your browser.

Only one database can be saved in your browser. If a database is already saved in your browser, it will not be overwritten. You must delete it before a new database can be saved in your browser. If the Delete button is disabled, this means no database is stored in your browser.

A KeyId is a short representation of a public key. It can be derived from the public key but not vice versa. This means you cannot verify a signed text that uses a KeyId for which you don't have the corresponding public key.

• Alt+P open password dialog
• Alt+C show/hide console
• Alt+W toggle word wrap in Sign & Verify tab
• Alt+R clear output messages in panes
• Alt+G generate 1000 keys when the Generate tab is open (you can use this to generate a key pair with a memorable KeyId)

• You can confirm your password by pressing enter
• On Firefox you can enable the option Use password input by browser without confirmation under Settings > More settings to auto-load your database without having to press enter
• When the Sign tab is open and you click on 🔍 in the database pane, the respective key is selected for signing instead of viewing
• Hover over certain UI elements to see an explanation
• If some emojis are not displayed correctly in the navigation, install the font Noto Color Emoji