About GOST Decryption Tool
The GOST block cipher (Magma), defined in the standard GOST 28147-89 (RFC 5830), is a Soviet and Russian government standard symmetric key block cipher with a block size of 64 bits. The original standard, published in 1989, did not give the cipher any name, but the most recent revision of the standard, GOST R 34.12-2015 (RFC 7801, RFC 8891), specifies that it may be referred to as Magma. The GOST hash function is based on this cipher. The new standard also specifies a new 128-bit block cipher called Kuznyechik. Developed in the 1970s, the standard had been marked 'Top Secret' and then downgraded to 'Secret' in 1990. Shortly after the dissolution of the USSR, it was declassified and it was released to the public in 1994. GOST 28147 was a Soviet alternative to the United States standard algorithm, DES. Thus, the two are very similar in structure.
Input: text. Output: text.
Format reference: GOST 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 | {"option":"Hex","string":"00112233"} | Key/text encoding: Hex, UTF8, Latin1, Base64 |
| IV | {"option":"Hex","string":"0011223344556677"} | Key/text encoding: Hex, UTF8, Latin1, Base64 |
| Input type | Hex | Hex, Raw |
| Output type | Raw | Raw, Hex |
| Algorithm | "GOST 28147 (1989)" | GOST 28147 (1989), GOST R 34.12 (Magma, 2015), GOST R 34.12 (Kuznyechik, 2015) |
| sBox | E-SC | E-TEST, E-A, E-B, E-C, E-D, E-SC, E-Z, D-TEST, D-A, D-SC |
| Block mode | OFB | ECB, CFB, OFB, CTR, CBC |
| Key meshing mode | CP | NO, CP |
| Padding | ZERO | NO, PKCS5, ZERO, RANDOM, BIT |
Sample keys and passwords are public. Never use them to protect real data.
Input
f124ac5c0853870906dbaf9b56
Result
Hello, World!
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 |
| Input type | Hex | Hex, Raw |
| Output type | Raw | Raw, Hex |
| Algorithm | "GOST 28147 (1989)" | GOST 28147 (1989), GOST R 34.12 (Magma, 2015), GOST R 34.12 (Kuznyechik, 2015) |
| sBox | E-TEST | E-TEST, E-A, E-B, E-C, E-D, E-SC, E-Z, D-TEST, D-A, D-SC |
| Block mode | ECB | ECB, CFB, OFB, CTR, CBC |
| Key meshing mode | NO | NO, CP |
| Padding | NO | NO, PKCS5, ZERO, RANDOM, BIT |
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.