About RC6 Decryption Tool
RC6 is a symmetric key block cipher derived from RC5. It was designed by Ron Rivest, Matt Robshaw, Ray Sidney, and Yiqun Lisa Yin to meet the requirements of the AES competition, and was one of the five finalists. RC6 is parameterised as RC6-w/r/b where w is word size in bits (any multiple of 8 from 8-256), r is the number of rounds (1-255), and b is the key length in bytes. The standard AES submission uses w=32, r=20. Common word sizes: 8, 16, 32 (standard), 64, 128. IV: The Initialisation Vector should be 4*w/8 bytes (e.g. 16 bytes for w=32). If not entered, it will default to null bytes. Padding: In CBC and ECB mode, the PKCS#7 padding scheme is used.
Input: text. Output: text.
Format reference: RC6 Decrypt background and specification
Example
Use “Try example” to load this public sample and its settings, then run it.
Settings used in this example
| Parameter | Example value | Input and choices |
|---|---|---|
| Key | {"string":"00010203","option":"Hex"} | Key/text encoding: Hex, UTF8, Latin1, Base64 |
| IV | {"string":"","option":"Hex"} | Key/text encoding: Hex, UTF8, Latin1, Base64 |
| Mode | ECB | CBC, CFB, OFB, CTR, ECB |
| Input | Hex | Hex, Raw |
| Output | Hex | Raw, Hex |
| Padding | NO | PKCS5, NO, ZERO, RANDOM, BIT |
| Word Size | 8 | Minimum: 8. Maximum: 256 |
| Rounds | 12 | Minimum: 1. Maximum: 255 |
Sample keys and passwords are public. Never use them to protect real data.
Input
aefc4612
Result
00010203
Parameters
| Parameter | Default value | Input and choices |
|---|---|---|
| Key | {"option":"Hex","string":""} | Key/text encoding: Hex, UTF8, Latin1, Base64 |
| IV | {"option":"Hex","string":""} | Key/text encoding: Hex, UTF8, Latin1, Base64 |
| Mode | CBC | CBC, CFB, OFB, CTR, ECB |
| Input | Hex | Hex, Raw |
| Output | Raw | Raw, Hex |
| Padding | PKCS5 | PKCS5, NO, ZERO, RANDOM, BIT |
| Word Size | 32 | Minimum: 8. Maximum: 256 |
| Rounds | 20 | Minimum: 1. Maximum: 255 |
Before interpreting the result
Use the exact key encoding, mode, padding and IV expected by the source system. Historical ciphers are useful for learning and analysis. Encoding alone provides no confidentiality.
How to use this page
- Paste your input or open a local file.
- Adjust tool options if needed, then choose Run tool.
- Copy the result or download the original output bytes.
Inputs and results are not added to the public catalogue or saved in the URL. Processing happens in your browser; HTTP Request and DNS over HTTPS send the requests you explicitly run. Files up to 128 MiB can be opened; decompression and image tools may have smaller processing limits. Large results have a shortened preview. Text and HTML downloads use UTF-8; binary downloads preserve output bytes. Pasted text follows browser newline handling; open a file when exact input bytes matter.