Encrypt / Decrypt
Encrypt and decrypt data with AES, DES, Triple DES, and RC4 symmetric ciphers
Choose an algorithm
For new applications, use AES — it is the only symmetric cipher here that is currently approved by NIST. The other algorithms are available for legacy interoperability and educational decryption only. For full status, key lengths, and deprecation dates, see our Symmetric Cipher Security Guide 2026 — sourced directly from NIST SP 800-131A Rev 2 and FIPS 197.
AES Encrypt / Decrypt
The Advanced Encryption Standard is the gold standard for symmetric encryption, adopted by NIST in 2001. Supports CBC, CFB, CTR, OFB, and ECB modes with configurable key sizes.
DES Encrypt / Decrypt
The Data Encryption Standard was the dominant cipher from the 1970s until it was publicly cracked in 1998 due to its short 56-bit key. Not suitable for protecting sensitive data.
Triple DES Encrypt / Decrypt
Triple DES applies the DES cipher three times with independent keys, providing stronger security than DES. Deprecated by NIST in 2023 in favor of AES.
RC4 Encrypt / Decrypt
RC4 is a fast stream cipher once widely used in SSL/TLS and WEP. Known statistical biases led to its prohibition in TLS (RFC 7465). Supports configurable key size and byte dropping.
Block vs stream ciphers, in one paragraph
All four algorithms are symmetric— the same secret key encrypts and decrypts. AES, DES, and Triple-DES are block ciphers: they process data in fixed-size blocks and require a mode of operation (CBC, CTR, CFB, OFB) to handle messages longer than one block. RC4 is a stream cipher: it produces a pseudorandom byte stream XOR'd with the plaintext, so no padding or mode is required. Detailed mode-selection guidance is in the cipher security guide.
Related guides
AES vs DES vs Triple DES: Encryption Algorithms Explained
An educational overview of symmetric encryption algorithms, their security levels, key sizes, and when to use each one in modern applications.
How to Password-Protect and Encrypt PDF Files
Step-by-step instructions for securing PDF documents with passwords and encryption, including permission controls and security best practices.