DES Encrypt

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

Single DES (56-bit effective, 8-byte key) Encryption (FIPS 46-3 Legacy)

Overview

Encrypts data using the legacy 64-bit Single Data Encryption Standard (DES) (FIPS 46-3) with an 8-byte key (56 effective key bits plus 8 parity bits) across CBC, ECB, CTR, CFB, or OFB modes.

Single DES is cryptographically broken due to its 56-bit key space and is provided strictly for legacy protocol interoperability (such as ISO/IEC 9797-1 Retail MACs, legacy smartcard APDUs, and educational Feistel network analysis).

When to Use

Reproducing legacy FIPS 46-3 test vectors, Retail MAC intermediate steps, or historical 8-byte block protocols.

Parameter Configuration

Parameter (ID)	Type & Default	Visibility Condition	Description & Options
Cipher Mode `mode`	`select` Default: `ECB`	Always visible	Selects `CBC`, `ECB`, `CTR`, `CFB`, or `OFB` mode. See Block Cipher Modes for full details. `ECB`: ECB (Electronic Codebook) `CBC`: CBC (Cipher Block Chaining)
Padding `padding`	`select` Default: `None`	Always visible	8-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#5 (RFC 2898) `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 (3 total; conditionally visible ports depend on parameter settings as shown below).

Port Name	Port ID	Data Type	Required	Visibility Condition	Description
`Key`	`key`	`Bytes` (8B)	Required	Always visible	8-byte (64-bit, 56-bit effective) DES key.
`Plaintext`	`plaintext`	`Bytes`	Required	Always visible	Plaintext bytes (`Uint8Array`) to encrypt.
`IV`	`iv`	`Bytes` (8B)	Optional	When `mode` is `CBC`	8-byte IV for `CBC`, `CTR`, `CFB`, and `OFB` modes (defaults to 8 zero bytes if unconnected).

Output Ports

Port Nature: Fixed Output Ports (1 total).

Port Name	Port ID	Data Type	Visibility Condition	Description
`Ciphertext`	`ciphertext`	`Bytes`	Always visible	Encrypted output bytes (`Uint8Array`).

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 not exactly 8 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 8 bytes.

Examples

Encrypting an 8-Byte Block with Single DES-ECB

Run a raw single-block DES encryption without padding.

Set Cipher Mode to ECB and Padding to None.
Connect an 8-byte key to Key and an 8-byte block to Plaintext.