About RC4 Drop
It was discovered that the first few bytes of the RC4 keystream are strongly non-random and leak information about the key. We can defend against this attack by discarding the initial portion of the keystream. This modified algorithm is traditionally called RC4-drop.
Input: text. Output: text.
Format reference: RC4 Drop 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 |
|---|---|---|
| Passphrase | {"option":"UTF8","string":"Key"} | Key/text encoding: UTF8, UTF16, UTF16LE, UTF16BE, Latin1, Hex, Base64 |
| Input format | UTF8 | Latin1, UTF8, UTF16, UTF16LE, UTF16BE, Hex, Base64 |
| Output format | Hex | Latin1, UTF8, UTF16, UTF16LE, UTF16BE, Hex, Base64 |
| Number of dwords to drop | 0 | Number |
Input
Plaintext
Result
bbf316e8d940af0ad3
Parameters
| Parameter | Default value | Input and choices |
|---|---|---|
| Passphrase | {"option":"UTF8","string":""} | Key/text encoding: UTF8, UTF16, UTF16LE, UTF16BE, Latin1, Hex, Base64 |
| Input format | Latin1 | Latin1, UTF8, UTF16, UTF16LE, UTF16BE, Hex, Base64 |
| Output format | Latin1 | Latin1, UTF8, UTF16, UTF16LE, UTF16BE, Hex, Base64 |
| Number of dwords to drop | 192 | Number |
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.
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