When you entrust an application with your most sensitive data, "military-grade encryption" is an overused marketing term. The reality is much more precise. Wispr uses AES-256-GCM, the gold standard for symmetric encryption. Here's what that actually means.
Advanced Encryption Standard (AES)
AES is a symmetric block cipher established by the U.S. National Institute of Standards and Technology (NIST) in 2001. "Symmetric" means the same key is used to both encrypt and decrypt the data. The "256" refers to the key size — 256 bits. A 256-bit key offers 2^256 possible combinations, a number so astronomically large that a brute-force attack using all the computing power on Earth would take billions of years.
Galois/Counter Mode (GCM)
Encryption alone only provides confidentiality (hiding the data). It does not provide integrity (proving the data hasn't been tampered with). An attacker might not be able to read the ciphertext, but they could flip bits, corrupting the message or potentially exploiting flaws in the decryption process.
GCM is a mode of operation that provides Authenticated Encryption with Associated Data (AEAD). It simultaneously encrypts the data and generates an authentication tag. During decryption, if the tag doesn't match — meaning a single bit of the ciphertext was altered — the decryption fails entirely.
Why Wispr Uses It
AES-256-GCM provides the perfect balance of unbreakable security, built-in tamper evidence, and exceptional performance. It is natively supported by modern browsers via the Web Crypto API, allowing Wispr to perform all cryptographic operations efficiently on your device without relying on external libraries. This choice is central to the zero-knowledge architecture — encryption runs in your browser, so the key never leaves your device. The broader implications of how self-destruct actually works explain why key management, not data deletion, is the real security guarantee.
