SEED Encrypt

Category: Symmetric Ciphers · Node Type ID: symmetric-seed-encrypt

KISA National Standard SEED 128/256-bit Block Cipher (RFC 4269)

Overview

Encrypts data using the Korean national standard 128-bit block cipher SEED (KISA TTAS.KO-12.0004 / ISO/IEC 18033-3 / RFC 4269). The node automatically selects between SEED-128 (16-round Feistel network, when a 16-byte key is connected) and SEED-256 (24-round Feistel network, when a 32-byte key is connected).

Supports CBC, GCM, CCM, CTR, ECB, CFB, and OFB modes over 16-byte blocks.

When to Use

Implementing Korean financial, government, or KCMVP-compliant cryptographic protocols requiring SEED-128 or SEED-256.
Validating KISA test vectors across CBC, CTR, GCM, or CCM modes.

Parameter Configuration

Parameter (ID)	Type & Default	Visibility Condition	Description & Options
Cipher Mode `mode`	`select` Default: `ECB`	Always visible	Selects the operating mode (`CBC`, `GCM`, `CCM`, `CTR`, `ECB`, `CFB`, or `OFB`) and adapts visible ports. See Block Cipher Modes for full details. `ECB`: ECB (Electronic Codebook) `CBC`: CBC (Cipher Block Chaining) `GCM`: GCM (AEAD) `CCM`: CCM (AEAD) `CTR`: CTR (Counter Mode)
Padding `padding`	`select` Default: `None`	Always visible	16-byte block padding scheme applied in `ECB` and `CBC` modes. See Padding Schemes for full details. `None`: None `Zero`: ISO/IEC 9797-1 Method 1 (Zero Padding) `ISO7816`: ISO/IEC 9797-1 Method 2 (ISO/IEC 7816-4) `ISO97971M3`: ISO/IEC 9797-1 Method 3 `PKCS7`: PKCS#7 (RFC 5652) `NIST80038B`: NIST SP 800-38B `ANSIX923`: ANSI X9.23
Unify Errors `errorUnify`	`boolean` Default: `false` Supports Variable Reference (`$var`: `bool`)	Always visible	Replaces built-in errors with a custom error code/message when enabled.
Unified Error Code `errorUnifyCode`	`text` Default: `""` (empty) Supports Variable Reference (`$var`: `string`)	When `errorUnify` is `true`	Custom error code when Unify Errors is enabled.
Unified Error Message `errorUnifyMessage`	`text` Default: `""` (empty) Supports Variable Reference (`$var`: `string`)	When `errorUnify` is `true`	Custom error message when Unify Errors is enabled.

Port I/O Specification

See Ports & Connections for general wiring rules, data type colors, and dynamic port creation.

Input Ports

Port Nature: Fixed Input Ports (5 total; conditionally visible ports depend on parameter settings as shown below).

Port Name	Port ID	Data Type	Required	Visibility Condition	Description
`Key`	`key`	`Bytes` (16/32B)	Required	Always visible	SEED secret key: `16` bytes (SEED-128) or `32` bytes (SEED-256).
`Plaintext`	`plaintext`	`Bytes`	Required	Always visible	Plaintext bytes (`Uint8Array`) to encrypt.
`IV`	`iv`	`Bytes` (16B)	Optional	When `mode` is `CBC` or `CTR`	16-byte IV or initial counter block for `CBC`, `CTR`, `CFB`, and `OFB` modes (defaults to 16 zero bytes if unconnected).
`Nonce`	`nonce`	`Bytes` (12B)	Optional	When `mode` is `GCM` or `CCM`	12-byte AEAD nonce for `GCM` and `CCM` modes (defaults to 12 zero bytes if unconnected).
`AAD`	`aad`	`Bytes` (GCM/CCM)	Optional	When `mode` is `GCM` or `CCM`	Optional Additional Authenticated Data for `GCM` and `CCM` modes.

Output Ports

Port Nature: Fixed Output Ports (2 total; conditionally visible ports depend on parameter settings as shown below).

Port Name	Port ID	Data Type	Visibility Condition	Description
`Ciphertext`	`ciphertext`	`Bytes`	Always visible	Encrypted output bytes (`Uint8Array`).
`Auth Tag`	`tag`	`Bytes` (GCM/CCM)	When `mode` is `GCM` or `CCM`	16-byte authentication tag produced in `GCM` and `CCM` modes.

Error Cases

When any of the following conditions occurs at runtime, this node transitions to an ERROR state and downstream nodes connected to its outputs do not execute. Enabling Unify Errors (errorUnify) replaces all error codes below with your configured unified error code and message.

Error Code	Default Engine Message	Trigger Condition
`INVALID_KEY_LENGTH`	Invalid key length	Raised when `Key` is neither 16 bytes (SEED-128) nor 32 bytes (SEED-256).
`INVALID_IV_LENGTH`	Invalid IV length	Raised when a connected `IV` is not 16 bytes or a connected `Nonce` is not 12 bytes.
`PLAINTEXT_NOT_BLOCK_ALIGNED`	In NoPad mode the plaintext length must be a multiple of the block size	Raised in `ECB`/`CBC` mode when `Padding = None` and `Plaintext` length is not a multiple of 16 bytes.
`INVALID_NONCE_LENGTH`	Invalid nonce length	Raised when a connected AEAD or stream-cipher `Nonce` is not 12 bytes (96 bits).

Examples

Encrypting with KISA SEED-128-CBC

Encrypt a UTF-8 message using a 16-byte SEED key in CBC mode with PKCS#7 padding.

Leave Cipher Mode set to CBC and Padding set to PKCS#7.
Connect a 16-byte key to Key, a 16-byte IV to IV, and your message bytes to Plaintext.