Data protection SDK for .NET — format-preserving encryption (FF1/FF3), data masking, and hashing.
dotnet add package Cyphera
using Cyphera;
// Auto-discover: checks CYPHERA_CONFIG_FILE env, ./cyphera.json, /etc/cyphera/cyphera.json
var c = Cyphera.Load();
// Or load from a specific file
var c = Cyphera.FromFile("./config/cyphera.json");
// Or inline config
var json = JsonDocument.Parse(@"{
""configurations"": {
""ssn"": { ""engine"": ""ff1"", ""key_ref"": ""my-key"", ""header"": ""T01"" }
},
""keys"": {
""my-key"": { ""material"": ""2B7E151628AED2A6ABF7158809CF4F3C"" }
}
}");
var c = Cyphera.FromConfig(json.RootElement);
// Protect
var encrypted = c.Protect("123-45-6789", "ssn");
// → "T01i6J-xF-07pX" (DPH-prefixed, dashes preserved)
// Access — the SDK uses the header to figure out the configuration
var decrypted = c.Access(encrypted);
// → "123-45-6789"| Engine | Reversible | Description |
|---|---|---|
ff1 |
Yes | NIST SP 800-38G FF1 format-preserving encryption |
ff3 |
Yes | NIST SP 800-38G Rev 1 FF3-1 format-preserving encryption |
mask |
No | Simple pattern masking (last4, first1, full, etc.) |
hash |
No | SHA-256/384/512, HMAC when key provided |
{
"configurations": {
"ssn": { "engine": "ff1", "key_ref": "my-key", "header": "T01" },
"cc": { "engine": "ff1", "key_ref": "my-key", "header": "T02" },
"ssn_mask": { "engine": "mask", "pattern": "last4", "header_enabled": false }
},
"keys": {
"my-key": { "material": "2B7E151628AED2A6ABF7158809CF4F3C" }
}
}The header (Data Protection Header, DPH) is a short prefix prepended to
protected output that identifies the configuration used. It lets Access()
reverse a value without the caller naming the configuration.
All SDKs produce identical output for the same inputs:
Input: 123-45-6789
Java: T01i6J-xF-07pX
Rust: T01i6J-xF-07pX
Node: T01i6J-xF-07pX
Python: T01i6J-xF-07pX
Go: T01i6J-xF-07pX
.NET: T01i6J-xF-07pX
Alpha. API is unstable. Cross-language test vectors validated against Java, Rust, Node, Python, and Go implementations.
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