DES / Triple DES (3DES) Encrypt & Decrypt
Encrypt or decrypt with DES or Triple DES (2-key or 3-key) in ECB, CBC, CFB, OFB or CTR mode, with PKCS#7, zero or no padding, hex or text keys and IVs.
DES was the US encryption standard from 1977 until AES replaced it; Triple DES (3DES) applies it three times with two or three keys and still appears in payment systems, smart cards, old databases and legacy file formats. This tool encrypts and decrypts with DES or 3DES in ECB, CBC, CFB, OFB and CTR modes, with PKCS#7, zero or no padding, keys and IVs as hex or text — useful for reading and testing legacy data. It runs in your browser.
How to use this tool
- Choose encrypt or decrypt, DES or Triple DES, and the mode.
- Enter the key (8, 16 or 24 bytes) and, except for ECB, the 8-byte IV.
- Pick the padding the other system uses (PKCS#7 is the usual one).
- Paste the data — text or hex to encrypt, Base64 or hex to decrypt — and copy the result.
Formula
3DES: C = E_K3( D_K2( E_K1(P) ) ), P = D_K1( E_K2( D_K3(C) ) )
DES encrypts 64-bit blocks with a 56-bit key (each key byte has a parity bit that is ignored) through 16 Feistel rounds. With a 16-byte key, K3 = K1 (2-key 3DES). CBC XORs each block with the previous ciphertext block (the IV for the first); CFB, OFB and CTR turn the block cipher into a stream, so no padding is needed. PKCS#7 adds 1–8 bytes each holding the pad length.
Example
The textbook DES example — key 133457799BBCDFF1, plaintext 0123456789ABCDEF — encrypts to 85E813540F0AB405. NIST’s Triple DES example in SP 800-67 (keys 0123456789ABCDEF, 23456789ABCDEF01, 456789ABCDEF0123, plaintext "The qufck brown fox jump") gives A826FD8CE53B855F CCE21C8112256FE6 68D5C05DD9B6B900.
Frequently asked questions
Is DES or 3DES still secure?
Single DES is not: its 56-bit key can be brute-forced. NIST deprecated Triple DES and disallowed it for new encryption after 2023, partly because its 64-bit block makes collisions likely after a few gigabytes (the Sweet32 attack). Use AES for anything new.
Why does decryption say the padding is wrong?
With PKCS#7 a wrong key, IV or mode almost always produces invalid padding, so the tool reports an error instead of showing garbage. If the data was encrypted without padding, choose "None".
How do I reproduce this with OpenSSL?
The result shows an openssl enc command with the same key and IV in hex. Single DES needs OpenSSL 3’s legacy provider, which the command enables.
Sources
Last updated:
Page address with these inputs: https://kakao.mobile/tools/des-encrypt-tool/
Cite or embed this tool
kakaoCalc. (2026, November 8). DES / Triple DES (3DES) Encrypt & Decrypt. https://kakao.mobile/tools/des-encrypt-tool/
“DES / Triple DES (3DES) Encrypt & Decrypt.” kakaoCalc, 8 Nov. 2026, kakao.mobile/tools/des-encrypt-tool/.
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