Vernam Cipher

31 reviews
Content rating
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About this app

Using this app, you can create and share secret keys that you can then use to encrypt and decrypt messages using the Vernam Cipher. This implementation acts as a one time pad as it discards the part of the key used to encrypt/decrypt messages.

Source code is available at

Changelog (from v1.1 onwards):

Version 1.10
- Upgraded Android SDK and Gradle versions.
- Updated the 'about' text.

Version 1.9:
- Fixed a couple of bugs that were causing crashes

Version 1.8
- Added a message to the user indicating their password protected secret keys are broken (terribly sorry everyone)

Version 1.7
- Fixed a bug that was causing secret key importing to fail.
- Fixed a bug that was causing password-protected secret keys to fail.

Version 1.6
- Fixed a bug that was causing the number of bytes remaining in a password-protected secret key to be misrepresented
- Added the display of the cipher text when decrypting a message.
- Added the ability to view a secret key (long press on a secret key in the list, then select 'View secret key').

Verison 1.5
- Fixed a bug that caused the app to crash when decryption was attempted with no secret keys generated

Version 1.4
- Fixed a bug that caused the app to crash on startup for new installations

Version 1.3
- Added ability to share encrypted messages as text or as a file - this opens up new sharing options
- Miscellaneous code cleanup
- Added a link to my donation page (yes, shameless self-promotion)

Version 1.2
- Fixed an error connecting to

Version 1.1
- Fixed a rather crippling Nougat bug
- Expanded the error message when data fetching fails
Updated on
Mar 6, 2020

Data safety

Developers can show information here about how their app collects and uses your data. Learn more about data safety
No information available
31 reviews
A Google user
March 7, 2020
An app (or any service) is as good as it's support. So, this app is not good - it's excellent. Jeff did an overnight fix for my fairly old KitKat device, so 5 star rating is the absolute minimum I can give. Keep up the good work!
2 people found this review helpful
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A Google user
March 6, 2020
Great app. It would also be great if a user could create their own pad and insert.
3 people found this review helpful
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Jeff Isaak
September 7, 2019
Thanks for the review. Well definitely add a scroll bar, and give some thought to user generated keys.
Roswell Grey
August 25, 2021
Used it to send memes ("Get stick bugged") to friends; kept crashing after two or three sent messages. Shame, was fun to use.
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What's new

Fixed TLS for KitKat. I hope.