AHE Lib APIs

A homomorphic encryption library file is provided for integrating the homomorphic encryption function in the client application during development.

The code for importing the library is import "ahe/PSW/api/ahelib".

GenerateKey

API prototype
func GenerateKey(pwd string) (privKeyStr string, pubKeyStr string, err error)
Function description
Generating a key pair for homomorphic encryption

Input

Parameter	Type	Description	Mandatory
pwd	string	Used to encrypt the generated private keychain used for homomorphic encryption. AES-128 is used for the encryption. The pwd value must contain: At least six characters At least two types of the following characters: Lowercase letters Uppercase letters Digits Spaces or special characters including `~!@#$%^&*()-_=+\\|[{}];:'",<.>/?	Yes

Parameter

Type

Description

Mandatory

pwd

string

Used to encrypt the generated private keychain used for homomorphic encryption. AES-128 is used for the encryption.

The pwd value must contain:

At least six characters
At least two types of the following characters:
- Lowercase letters
- Uppercase letters
- Digits
- Spaces or special characters including `~!@#$%^&*()-_=+\|[{}];:'",<.>/?

Yes

Output

Parameter	Type	Description
privKeyStr	string	Homomorphic private key encrypted using the pwd
pubKeyStr	string	Public keychain for homomorphic encryption
err	error	Error message

Note
The complexity of keys depends on the actual application scenario. No restrictions need to be imposed on a key used to invoke an underlying library.

Encypt

API prototype
func Encypt (secretNumStr string, pubKeyStr string) (ciphertext string, err error)
Function description
Homomorphic encryption

Input

Parameter	Type	Description	Mandatory
secretNumStr	string	Value to be encrypted. The value must be a positive integer greater than or equal to 0. If the number contains decimal places, the value must be multiplied to eliminate the decimal places.	Yes
pubKeyStr	String	Public key for homomorphic encryption	Yes

Output

Parameter	Type	Description
ciphertext	string	Encrypted data
err	error	Error message

Note
None

Decrypt

API prototype
func Decrypt(ciphertext string, privKeyStr string, pwd string) (plainText *big.Int, err error)
Function description
Homomorphic decryption

Input

Parameter	Type	Description	Mandatory
ciphertext	string	Ciphertext to be decrypted	Yes
privKeyStr	string	Private keychain encrypted using the pwd for protection	Yes
pwd	string	Character string used to protect the private key	No

Output

Parameter	Type	Description
plainText	*big.int	Decrypted data
err	error	Error message

Note
None

Add

API prototype
func Add(cipher1, cipher2 string) (cipher string, err error)
Function description
Additive homomorphic encryption

Input

Parameter	Type	Description	Mandatory
cipher1	string	Encrypted ciphertext 1	Yes
cipher2	string	Encrypted ciphertext 2	Yes

Output

Parameter	Type	Description
cipher	string	Combined data
err	error	Error message

Note
None

InitBalance

API prototype
func InitBalance(balanceStr string, pubKey string) (string, error)
Function description
Balance initialization

Input

Parameter	Type	Description	Mandatory
pubKey	string	Public keychain	Yes
balanceStr	string	Initial balance, which must be a positive integer greater than or equal to 0. If the number contains decimal places, the value must be multiplied to eliminate the decimal places.	Yes

Output

Parameter	Type	Description
balanceInfo	string	Transaction amount information
err	error	Error message

Note
None

PrepareTxInfo

API prototype
func PrepareTxInfo(cipherBalanceA string, transNumStr string, pubKeyA, pubKeyB string, privKeyA string,pwd string) (string, error)
Function description
Transaction preparation

Input

Parameter	Type	Description	Mandatory
cipherBalanceA	string	Current balance of user A (ciphertext), which is obtained from the blockchain.	Yes
transNumStr	string	Transfer amount (plaintext)	Yes
pubKeyA	string	Public keychain of user A	Yes
pubKeyB	string	Public keychain of user B	Yes
PrivKeyA	string	Private keychain of user A	Yes
pwd	string	Character string used for encryption	No