SeeOnce Privacy Firefox

SeeOnce Privacy

By: F. Ruiz
High strength end-to-end encryption with perfect forward secrecy for your favorite email, plus real-time secure chat

Features & Capabilities

SeeOnce encrypts your email messages so they self-destruct after the recipient has read them. It does this without involving any servers or forcing you to make an account anywhere. You can keep using your preferred email.

All other apps and extensions store your private content somewhere. SeeOnce does not do this; instead, it achieves forward secrecy by changing encryption keys with every message. This way, you don't have to trust anybody. Not even SeeOnce.

When you get a SeeOnce-locked message, just paste it into SeeOnce and it will open automatically. Then you can reply directly from SeeOnce.

Your friends don't need to have the SeeOnce add-on. Messages open in a webpage just by clicking them. They can do this on an Android smartphone if necessary.

Some people live in places where using encryption is itself compromising. This is why SeeOnce can disguise its output so it looks like normal text. Just supply a sufficiently long cover text after the message is locked. Disguised messages also unlock as soon as you paste them into SeeOnce.

If you find yourself exchanging a lot of emails, SeeOnce allows you to switch to real-time chat, which can involve text, files, audio, or even video. Just click the Chat button to make a secure invitation that only your recipient can open, and then only once.

SeeOnce has comprehensive help just one click away.

SeeOnce uses 255-bit standard elliptic curves, which have been vetted against weaknesses by experts. On top of that, SeeOnce uses 256-bit XSalsa20 encryption and 512-bit hash functions to complete the locking process. XSalsa20 is a high-performance, open source cipher, which has been scrutinized by experts for nearly a decade without any practical weaknesses being found.

This is the Firefox add-on version of SeeOnce Privacy, essentially identical to the web version, except that it syncs its data seamlessly between machines.

The following is to check the authenticity of the web version of SeeOnce:

Current version of SeeOnce is: 1.2.6 Main source: https://PassLok.com/SeeOnce

SHA256 string for web source (single html file):

403e-93b4-3091-6074-36bc-4133-0829-d259-b688-f209-800f-fa8a-619d-98e7-6365-0095

Watch author F. Ruiz reading this string:

https://www.youtube.com/watch?v=r8E8OUFYpdA

User Growth & Download Statistics

Manifest V3 Add-on
By:
F. Ruiz
Daily users:
1
Rating:
5.00
(1)
Version:
1.2.13 Last updated: 2023-03-23
Version code:
5543625
Creation date:
2017-11-13
Risk:
Very low risk impact Low risk likelihood
Permissions:
Size:
141.19KB
Email:
fr*****@gmail.com
URLs:
Website
Full description:
See detailed description
Source:
Firefox Add-ons Store
Data ingested on:
2026-07-06
Compare stats and ranking:

Contact the developer

Chrome-Stats does not own this Firefox add-on. Please use these information below to contact the Firefox add-on developer.
Developed by:
F. Ruiz
Firefox Add-ons Store
https://addons.mozilla.org/firefox/addon/seeonce-privacy/
Email:
fr*****@gmail.com
Website:
http://see-once.weebly.com

User Reviews

Of course it would need an audit to be bullet proof.
by tp*****, 2017-11-17
View all user reviews ›

Is SeeOnce Privacy Safe?

Risk impact
Risk impact measures the level of extra permissions an extension has access to. A low risk impact extension cannot do much harms, whereas a high risk impact extension can do a lot of damage like stealing your password, bypassing your security settings, and accessing your personal data. High risk impact extensions are not necessarily malicious. However, if they do turn malicious, they can be very harmful.

SeeOnce Privacy does not require any sensitive permissions.

Risk impact analysis details
Risk likelihood
Risk likelihood measures the probability that a Firefox add-on may turn malicious. This is determined by the publisher and the Firefox add-on reputation on Firefox Add-ons Store, the amount of time the Firefox add-on has been around, and other signals about the Firefox add-on. Our algorithms are not perfect, and are subject to change as we discover new ways to detect malicious extensions. We recommend that you always exercise caution when installing a Firefox add-on.

SeeOnce Privacy has earned a fairly good reputation and likely can be trusted.

Risk likelihood analysis details
  • High This extension has low user count. Unpopular extensions may not be stable or safe.
  • Low **** ********* *** ******* **** **** * ****** **** ***** ******** *** **** ****** ** ** ****** *** *****
  • Low **** ********* *** ***** **** **** * ****** **** ***** ********** *** **** ****** ** ** ****** *** *****
  • Good **** ********* *** **** **** *******
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