Package net.finmath.decryptionoracle.decryption

Class DecryptionOracleImplementation

java.lang.Object

net.finmath.decryptionoracle.decryption.DecryptionOracleImplementation

All Implemented Interfaces:

DecryptionOracle

public class DecryptionOracleImplementation
extends Object
implements DecryptionOracle

Implementation of a DecryptionOracle using RSA.

Author:

Christian Fries

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static enum	DecryptionOracleImplementation.KeyFormat	Spcifies the desired key format.

Constructor Summary

Constructors

Constructor	Description
DecryptionOracleImplementation(PublicKey publicKey)	Constructor for DecryptionOracleImplementation.
DecryptionOracleImplementation(PublicKey publicKey, PrivateKey privateKey)	Constructor for DecryptionOracleImplementation.
DecryptionOracleImplementation(PublicPrivateEncryptionDecryption method, PublicKey publicKey, PrivateKey privateKey)	Constructor for DecryptionOracleImplementation.
DecryptionOracleImplementation(PublicPrivateEncryptionDecryption method, PublicKey publicKey, PrivateKey privateKey, UnaryOperator<byte[]> hashingMethod)	Construct the DecryptionOracleImplementation.
DecryptionOracleImplementation(PublicPrivateEncryptionDecryption method, PublicKey publicKey, PrivateKey privateKey, DecryptionOracleImplementation.KeyFormat keyFormat, UnaryOperator<byte[]> hashingMethod)	Construct the DecryptionOracleImplementation.

Method Summary

Modifier and Type	Method	Description
byte[]	decrypt(byte[] encryptedKey)	Decrypt an encrypted key E(K).
byte[]	decrypt(PrivateKey key, byte[] ciphertext)	decrypt.
byte[]	encrypt(PublicKey key, byte[] text)	encrypt.
EncryptedHashedKey	generateEncryptedHashedKey(String contract, byte[] transaction)	Generate a key for a given contract and transaction.
byte[]	generateKey(String contract, byte[] transaction)	Generate a key K for a given contract and transaction.
KeyVerification	verify(byte[] encryptedKey)	From an encrypted key E(K) generated the KeyVerification.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface net.finmath.decryptionoracle.decryption.DecryptionOracle

decryptIfVerified

Constructor Details

DecryptionOracleImplementation

public DecryptionOracleImplementation(PublicPrivateEncryptionDecryption method,
 PublicKey publicKey,
 PrivateKey privateKey,
 DecryptionOracleImplementation.KeyFormat keyFormat,
 UnaryOperator<byte[]> hashingMethod)

Construct the DecryptionOracleImplementation.

Parameters:

method - a PublicPrivateEncryptionDecryption object

publicKey - a PublicKey object

privateKey - a PrivateKey object

keyFormat - the format of the generated key K (i.e. what the byte sequence represents: XML UTF-8 string, or hex string)

hashingMethod - the hashing algorithm as a UnaryOperator

DecryptionOracleImplementation

public DecryptionOracleImplementation(PublicPrivateEncryptionDecryption method,
 PublicKey publicKey,
 PrivateKey privateKey,
 UnaryOperator<byte[]> hashingMethod)

Construct the DecryptionOracleImplementation.

Parameters:

method - a PublicPrivateEncryptionDecryption object

publicKey - a PublicKey object

privateKey - a PrivateKey object

hashingMethod - a UnaryOperator object

DecryptionOracleImplementation

public DecryptionOracleImplementation(PublicPrivateEncryptionDecryption method,
 PublicKey publicKey,
 PrivateKey privateKey)

Constructor for DecryptionOracleImplementation.

Parameters:

method - a PublicPrivateEncryptionDecryption object

publicKey - a PublicKey object

privateKey - a PrivateKey object

DecryptionOracleImplementation

public DecryptionOracleImplementation(PublicKey publicKey,
 PrivateKey privateKey)

Constructor for DecryptionOracleImplementation.

Parameters:

publicKey - a PublicKey object

privateKey - a PrivateKey object

DecryptionOracleImplementation

public DecryptionOracleImplementation(PublicKey publicKey)

Constructor for DecryptionOracleImplementation.

Parameters:

publicKey - a PublicKey object

Method Details

decrypt

public byte[] decrypt(byte[] encryptedKey)

Decrypt an encrypted key E(K).

Specified by:

decrypt in interface DecryptionOracle

Parameters:

encryptedKey - The encrypted key.

Returns:

The decrypted key K.

verify

public KeyVerification verify(byte[] encryptedKey)

From an encrypted key E(K) generated the KeyVerification. Take and encrypted key E(K) and generate the verification information, including H(K).

Specified by:

verify in interface DecryptionOracle

Parameters:

encryptedKey - The encrypted key E(K).

Returns:

The key verification consisting of the hash H(K), the contract and the transaction.

generateKey

public byte[] generateKey(String contract,
 byte[] transaction)

Generate a key K for a given contract and transaction. Encryption should be performed client side and it is recommended to call verify on the encrypted key K. The advantage of this procedure is that the caller obtains ownership to the key K in case of a failure of the decryption oracle to allow for a legally secured fall back method.

Specified by:

generateKey in interface DecryptionOracle

Parameters:

contract - A string identifying the contract.

transaction - A string identifying the transaction.

Returns:

The key K.

generateEncryptedHashedKey

public EncryptedHashedKey generateEncryptedHashedKey(String contract,
 byte[] transaction)

Generate a key for a given contract and transaction.

Specified by:

generateEncryptedHashedKey in interface DecryptionOracle

Parameters:

contract - A string identifying the contract.

transaction - A string identifying the transaction.

Returns:

The pair of encrypted key E(K) and hashed key H(K) for the generated key K.

encrypt

public byte[] encrypt(PublicKey key,
 byte[] text)

encrypt.

Parameters:

key - a PublicKey object

text - an array of bytes objects

Returns:

an array of bytes objects

decrypt

public byte[] decrypt(PrivateKey key,
 byte[] ciphertext)

decrypt.

Parameters:

key - a PrivateKey object

ciphertext - an array of bytes objects

Returns:

an array of bytes objects