StealthChat uses end-to-end encryption technology to encrypt
your messages, files and calls in transit. This provides an
additional layer of protection over industry standard SSL/TLS.
The end-to-end encryption means that only you and the receiver
can read them. Each session is encrypted with a unique key pair
and in the extreme event that your connection is monitored the
data still cannot be decrypted. The message encryption is based
on the "Off-the-record" (OTR) Messaging protocol:
The Voice Over IP (VoIP) encryption is based on the Secure Real Time Transport (SRTP) protocol:
StealthChat automates the end-to-end key exchange when the communication session is initiated and the keys are used to encrypt calls, chats and files. Unlike some other "secure" apps, StealthChat encrypts all communication to ensure that unencrypted information cannot be exchanged inadvertently.
StealthChat provides a unique and optional screen encryption.
Information on the StealthChat screen can be set to switch to
encrypted mode. The screen is encrypted after a timeout period
or after the app is sent to the background. The encrypted screen
mode can be unlocked with a password, with a picture lock or
with TouchID. This feature protects against "shoulder surfing"
where somebody looks over your shoulder or picks up your phone
when the device is unlocked. The Encrypted Display prevents
unauthorized users from viewing your message history or who you
have been talking with.
StealthChat stores your message history securely on disk using
industry best practices including AES/EAX encryption using a
PBKDF derived password. In addition, you can set a burn timer
for your messages, after which they are deleted from disk on
your device and your friend's device.