No. DES has a 56-bit effective key size and is vulnerable to brute-force attacks with modern hardware in hours. 3DES is deprecated by NIST as of 2023. Use AES-256 for any real security requirement.

Why is this tool provided if DES is insecure?

Legacy systems, academic study, and compatibility testing still require DES. This tool provides a convenient browser-based implementation for those purposes.

What mode and padding does this tool use?

ECB (Electronic Codebook) mode with PKCS7 padding. ECB does not use an IV, which is one of several reasons it is unsuitable for modern use.

What is Triple-DES (3DES)?

3DES applies DES encryption three times using a 24-byte (168-bit effective) key in EDE (Encrypt-Decrypt-Encrypt) mode. It is stronger than single DES but still deprecated.

What format is the ciphertext output?

The output is uppercase hexadecimal. To decrypt, paste the same hex string back into the decrypt mode with the same key.

What is PKCS7 padding?

PKCS7 padding ensures the plaintext is a multiple of the 8-byte DES block size. The padding byte value equals the number of padding bytes added.

Can I use this to interoperate with OpenSSL DES-ECB?

Yes, for the same key and data. Note that OpenSSL expects keys in binary by default; you will need to pass the -K hex flag to match this tool's hex key format.

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DES / 3DES Cipher

Encrypt and decrypt data with legacy DES (8-byte key) or Triple-DES (24-byte key) using ECB mode with PKCS7 padding.

⚠ Security Warning: DES and 3DES are legacy ciphers considered cryptographically weak. DES has a 56-bit effective key size and is vulnerable to brute-force attacks. 3DES is deprecated by NIST as of 2023. Use AES-256 for any real security needs. This tool is for educational and legacy compatibility purposes only.

Key (hex, 16 chars)

Plaintext

DES and 3DES cipher: legacy encryption for educational and compatibility use

DES (Data Encryption Standard) was the US federal standard for symmetric encryption from 1977 to 2001. It uses a 56-bit key and operates on 64-bit blocks through 16 rounds of Feistel network substitution and permutation. While DES itself is considered cryptographically broken due to its short key length, understanding it remains foundational to studying modern cipher design.

This tool implements the full DES algorithm in pure JavaScript, running entirely in your browser with no server communication. It supports both single DES and Triple-DES (EDE mode) with ECB block chaining and PKCS7 padding: sufficient for legacy interoperability and academic purposes.

How to use: step by step

1
Select the algorithm
Choose DES (8-byte / 16 hex-char key) or 3DES / Triple-DES (24-byte / 48 hex-char key).
2
Select Encrypt or Decrypt
Encrypt converts plaintext to a hex ciphertext. Decrypt converts a hex ciphertext back to plaintext.
3
Enter the key in hex
Type the key as hexadecimal characters. A pre-filled example key is provided. Keys must be exactly 16 or 48 hex characters respectively.
4
Enter the input
Paste your plaintext (for encryption) or your hex ciphertext (for decryption). The tool uses ECB mode with PKCS7 padding.
5
Click Encrypt / Decrypt and copy the result
The result is displayed as hex output. Copy it with the Copy button.

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Frequently Asked Questions

Is DES secure?: No. DES has a 56-bit effective key size and is vulnerable to brute-force attacks with modern hardware in hours. 3DES is deprecated by NIST as of 2023. Use AES-256 for any real security requirement.
Why is this tool provided if DES is insecure?: Legacy systems, academic study, and compatibility testing still require DES. This tool provides a convenient browser-based implementation for those purposes.
What mode and padding does this tool use?: ECB (Electronic Codebook) mode with PKCS7 padding. ECB does not use an IV, which is one of several reasons it is unsuitable for modern use.
Is my data sent to a server?: No. The DES implementation is pure JavaScript running entirely in your browser tab. No network request is made.
What is Triple-DES (3DES)?: 3DES applies DES encryption three times using a 24-byte (168-bit effective) key in EDE (Encrypt-Decrypt-Encrypt) mode. It is stronger than single DES but still deprecated.
What format is the ciphertext output?: The output is uppercase hexadecimal. To decrypt, paste the same hex string back into the decrypt mode with the same key.
What is PKCS7 padding?: PKCS7 padding ensures the plaintext is a multiple of the 8-byte DES block size. The padding byte value equals the number of padding bytes added.
Can I use this to interoperate with OpenSSL DES-ECB?: Yes, for the same key and data. Note that OpenSSL expects keys in binary by default; you will need to pass the -K hex flag to match this tool's hex key format.

AlteredIdea vs alternatives

vs online hashing sites: Many send your data to a server to hash it. AlteredIdea runs all cryptographic operations in your browser using the Web Crypto API: your sensitive data never leaves your device.

vs openssl / command line: No terminal, no setup. Just paste and get results instantly.

vs library code: No coding required. Instant visual output with copy-to-clipboard.

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