BlindData (Javadocs [I2P+ 2.11.0+] - API Version 0.9.68+)

java.lang.Object
- net.i2p.data.BlindData

```
public class BlindData
extends Object
```
Cache data for EdDSA key blinding as specified in Proposal 123: New NetDb Entries.
BlindData provides the infrastructure for cryptographic key blinding in I2P:
- Manages blinded and unblinded EdDSA signing key pairs
- Supports multiple authentication methods for encrypted LeaseSets
- Caches computed blinded keys and related metadata
- Handles time-based key rotation and expiration
- Generates blinded destination addresses (.b32.i2p)
Key Components:
- Key Blinding: Transforms clear signing keys into blinded equivalents
- Authentication: Supports DH, PSK, and no-authentication modes
- Caching: Stores computed values to avoid expensive recalculation
- Address Generation: Creates blinded .b32 addresses for services
Authentication Types:
- AUTH_NONE - No authentication required
- AUTH_DH - Diffie-Hellman key exchange for per-client keys
- AUTH_PSK - Pre-shared key authentication
Usage Scenarios:
- Encrypted LeaseSets: Generate blinded keys for restricted access
- Destination Blinding: Create anonymous service endpoints
- Access Control: Implement authentication for private services
- Key Rotation: Manage time-based blinded key updates
Security Considerations:
- Blinded keys provide unlinkability between clear and blinded identities
- Authentication data must be securely stored and transmitted
- Key rotation intervals should balance security and usability
- Proper validation of blinded signatures is essential
Implementation Status: PRELIMINARY - Subject to change as proposal evolves

Field Summary

Fields
Modifier and Type	Field and Description
`static int`	`AUTH_DH` bits 3-0 including per-client bit
`static int`	`AUTH_NONE` bits 3-0 including per-client bit
`static int`	`AUTH_ON` Enabled, unspecified type
`static int`	`AUTH_PSK` bits 3-0 including per-client bit

Constructor Summary

Constructors
Constructor and Description
`BlindData(I2PAppContext ctx, Destination dest, SigType blindType, String secret)` Creates a new BlindData instance for the given destination.
`BlindData(I2PAppContext ctx, Destination dest, SigType blindType, String secret, int authType, PrivateKey authKey)` Creates a new BlindData instance for the given destination with authentication.
`BlindData(I2PAppContext ctx, SigningPublicKey spk, SigType blindType, String secret)`
`BlindData(I2PAppContext ctx, SigningPublicKey spk, SigType blindType, String secret, int authType, PrivateKey authKey)` Creates a new BlindData instance for the given signing public key with authentication.

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`SigningPrivateKey`	`getAlpha()` Gets the alpha value for the current day.
`PrivateKey`	`getAuthPrivKey()` Gets the authentication private key.
`boolean`	`getAuthRequired()` Checks if authentication is required.
`int`	`getAuthType()` Gets the authentication type.
`Hash`	`getBlindedHash()` Gets the hash of the blinded key for the current day.
`SigningPublicKey`	`getBlindedPubKey()` Gets the blinded signing public key for the current day.
`SigType`	`getBlindedSigType()` Gets the type of the blinded signature.
`long`	`getDate()` Creation date.
`Hash`	`getDestHash()` Gets the destination hash if known.
`Destination`	`getDestination()` Gets the destination if known.
`long`	`getExpiration()` Expiration date.
`String`	`getSecret()` Gets the secret if set.
`boolean`	`getSecretRequired()` Checks if a secret is required.
`SigningPublicKey`	`getUnblindedPubKey()` Gets the unblinded signing public key.
`void`	`setAuthRequired()` Marks that authentication is required for this blinded key.
`void`	`setDate(long date)` Creation date.
`void`	`setDestination(Destination d)` Sets the destination for this blinded data.
`void`	`setExpiration(long date)` Expiration date.
`void`	`setSecretRequired()` Marks that a secret is required for this blinded key.
`String`	`toBase32()` Encodes the blinded key in b33 format.
`String`	`toString()`

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

- Field Detail
  - AUTH_DH
```
public static final int AUTH_DH
```
    bits 3-0 including per-client bit
    
    See Also:
    
    Constant Field Values
  - AUTH_NONE
```
public static final int AUTH_NONE
```
    bits 3-0 including per-client bit
    
    See Also:
    
    Constant Field Values
  - AUTH_ON
```
public static final int AUTH_ON
```
    Enabled, unspecified type
    
    See Also:
    
    Constant Field Values
  - AUTH_PSK
```
public static final int AUTH_PSK
```
    bits 3-0 including per-client bit
    
    See Also:
    
    Constant Field Values
- Constructor Detail
  - BlindData
```
public BlindData(I2PAppContext ctx,
                 Destination dest,
                 SigType blindType,
                 String secret)
```
    Creates a new BlindData instance for the given destination.
    
    Parameters:
    
    ctx - the application context
    
    dest - the destination
    
    blindType - the type of blinded signature
    
    secret - may be null or zero-length
    
    Throws:
    
    IllegalArgumentException - on various errors
  - BlindData
```
public BlindData(I2PAppContext ctx,
                 Destination dest,
                 SigType blindType,
                 String secret,
                 int authType,
                 PrivateKey authKey)
```
    Creates a new BlindData instance for the given destination with authentication.
    
    Parameters:
    
    ctx - the application context
    
    dest - the destination
    
    blindType - the type of blinded signature
    
    secret - may be null or zero-length
    
    authType - the authentication type
    
    authKey - the authentication key
    
    Throws:
    
    IllegalArgumentException - on various errors
  - BlindData
```
public BlindData(I2PAppContext ctx,
                 SigningPublicKey spk,
                 SigType blindType,
                 String secret)
```
    Parameters:
    
    secret - may be null or zero-length
    
    Throws:
    
    IllegalArgumentException - on various errors
  - BlindData
```
public BlindData(I2PAppContext ctx,
                 SigningPublicKey spk,
                 SigType blindType,
                 String secret,
                 int authType,
                 PrivateKey authKey)
```
    Creates a new BlindData instance for the given signing public key with authentication.
    
    Parameters:
    
    ctx - the application context
    
    spk - the signing public key
    
    blindType - the type of blinded signature
    
    secret - may be null or zero-length
    
    authType - the authentication type
    
    authKey - the authentication key
    
    Throws:
    
    IllegalArgumentException - on various errors
- Method Detail
  - getAlpha
```
public SigningPrivateKey getAlpha()
```
    Gets the alpha value for the current day.
    
    Returns:
    
    Alpha for the current day
  - getAuthPrivKey
```
public PrivateKey getAuthPrivKey()
```
    Gets the authentication private key.
    
    Returns:
    
    null for no client auth
  - getAuthRequired
```
public boolean getAuthRequired()
```
    Checks if authentication is required.
    
    Returns:
    
    true if authentication is required
  - getAuthType
```
public int getAuthType()
```
    Gets the authentication type.
    
    Returns:
    
    0 for no client auth, 1 for DH, 3 for PSK
  - getBlindedHash
```
public Hash getBlindedHash()
```
    Gets the hash of the blinded key for the current day.
    
    Returns:
    
    The hash of the blinded key for the current day
  - getBlindedPubKey
```
public SigningPublicKey getBlindedPubKey()
```
    Gets the blinded signing public key for the current day.
    
    Returns:
    
    The blinded key for the current day, non-null
  - getBlindedSigType
```
public SigType getBlindedSigType()
```
    Gets the type of the blinded signature.
    
    Returns:
    
    The type of the blinded key
  - getDate
```
public long getDate()
```
    Creation date. Absolute timestamp. Returns zero if not specified.
    
    Returns:
    
    creation date or as overridden by setDate()
  - getDestHash
```
public Hash getDestHash()
```
    Gets the destination hash if known.
    
    Returns:
    
    The hash of the destination if known, or null
  - getDestination
```
public Destination getDestination()
```
    Gets the destination if known.
    
    Returns:
    
    null if unknown
  - getExpiration
```
public long getExpiration()
```
    Expiration date. Absolute timestamp. Returns zero if not specified.
    
    Returns:
    
    expiration date or as overridden by setExpiration()
  - getSecret
```
public String getSecret()
```
    Gets the secret if set.
    
    Returns:
    
    null if none
  - getSecretRequired
```
public boolean getSecretRequired()
```
    Checks if a secret is required.
    
    Returns:
    
    true if a secret is required
  - getUnblindedPubKey
```
public SigningPublicKey getUnblindedPubKey()
```
    Gets the unblinded signing public key.
    
    Returns:
    
    The unblinded SPK, non-null
  - setAuthRequired
```
public void setAuthRequired()
```
    Marks that authentication is required for this blinded key.
  - setDate
```
public void setDate(long date)
```
    Creation date. Absolute timestamp.
    
    Parameters:
    
    date - the creation date in milliseconds
  - setDestination
```
public void setDestination(Destination d)
```
    Sets the destination for this blinded data.
    
    Parameters:
    
    d - the destination to set
    
    Throws:
    
    IllegalArgumentException - on SigningPublicKey mismatch
  - setExpiration
```
public void setExpiration(long date)
```
    Expiration date. Absolute timestamp.
    
    Parameters:
    
    date - the expiration date in milliseconds
  - setSecretRequired
```
public void setSecretRequired()
```
    Marks that a secret is required for this blinded key.
  - toBase32
```
public String toBase32()
```
    Encodes the blinded key in b33 format. Encodes the blinded key in b33 format.
    
    Returns:
    
    the b33 encoded string
  - toString
```
public String toString()
```
    Overrides:
    
    toString in class Object

Class BlindData

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

AUTH_DH

AUTH_NONE

AUTH_ON

AUTH_PSK

Constructor Detail

BlindData

BlindData

BlindData

BlindData

Method Detail

getAlpha

getAuthPrivKey

getAuthRequired

getAuthType

getBlindedHash

getBlindedPubKey

getBlindedSigType

getDate

getDestHash

getDestination

getExpiration

getSecret

getSecretRequired

getUnblindedPubKey

setAuthRequired

setDate

setDestination

setExpiration

setSecretRequired

toBase32

toString