AES-256
AES-256 is a symmetric encryption algorithm standardized by NIST that uses 256-bit keys. It's one of the most widely used and audited block ciphers in the world.
AES (Advanced Encryption Standard) is a symmetric block cipher adopted as a standard by NIST in 2001. AES-256 uses a 256-bit key, making it resistant to brute-force attacks with current technology and for the foreseeable future.
AES alone defines how a single block of data is encrypted, but it needs a 'mode of operation' to securely encrypt messages of arbitrary length. Modes like GCM (Galois/Counter Mode) additionally add authentication: they let you detect whether the ciphertext was tampered with, not just hide it.
V4ult encrypts vault content (passwords, notes, cards, OTP codes) field-by-field using AES-256 in GCM mode, via Dart's `cryptography` package. The symmetric key used for this encryption is generated randomly per vault and is itself protected by wrapping it with a key derived from the user's master password (see zero-knowledge).
Advantages
- Publicly audited standard for over two decades
- Resistant to brute force with current technology
- GCM mode adds authentication, not just confidentiality
Related
Frequently asked questions
What is AES-256?
AES-256 is a symmetric encryption algorithm with 256-bit keys, standardized by NIST. It's one of the most widely used and studied ciphers worldwide for protecting data at rest and in transit.
Is AES-256 alone enough to encrypt data securely?
Not exactly: AES-256 needs a mode of operation (such as GCM) that defines how to encrypt full messages and, in GCM's case, also verifies that the ciphertext wasn't altered.
What encryption algorithm does V4ult use?
V4ult encrypts vault content field-by-field with AES-256 in GCM mode, using Dart's `cryptography` package.