# Block-ciphers

## Block ciphers

[DES algorithm video - 1](https://www.youtube.com/watch?v=kPBJIhpcZgE\&index=5\&list=PL6N5qY2nvvJE8X75VkXglSrVhLv1tVcfy)

[DES algorithm video - 2](https://www.youtube.com/watch?v=l-7YW06BFNs\&index=6\&list=PL6N5qY2nvvJE8X75VkXglSrVhLv1tVcfy)

In order to understand *hex* and *type* parameters read [Hash](https://github.com/liesware/coherence/wiki/Hash)

In order to understand encryption and decryption read [Stream](https://github.com/liesware/coherence/wiki/Stream)

### AES

[spec](http://www.quadibloc.com/crypto/co040401.htm)

[AES algorithm video - 1](https://www.youtube.com/watch?v=x1v2tX4_dkQ\&list=PL6N5qY2nvvJE8X75VkXglSrVhLv1tVcfy\&index=7)

[AES algorithm video - 2](https://www.youtube.com/watch?v=NHuibtoL_qk\&list=PL6N5qY2nvvJE8X75VkXglSrVhLv1tVcfy\&index=8)

Description: Block cipher and AES winner.

Key:128, 192, 256 bits.

Iv: 128 bits.

Uses: General propuse, Performance is impportant, FIPS 197, NIST.

### RC6

[spec](https://en.wikipedia.org/wiki/RC6)

Description: Block cipher and AES finalist.

Key: 128, 192, 256 bits.

Iv: 128 bits.

Uses: General propuse, alternative to AES.

### MARS

[spec](http://www.quadibloc.com/crypto/co040406.htm)

Description: Block cipher and AES finalist.

Key: 128, 192, 256 bits.

Iv: 128 bits.

Uses: General propuse, alternative to AES.

### Twofish

[spec](https://www.schneier.com/academic/twofish/)

Description: Block cipher and AES finalist.

Key: 128, 192, 256 bits.

Iv: 128 bits.

Uses: General propuse, alternative to AES.

### Serpent

[spec](http://www.cl.cam.ac.uk/~rja14/serpent.html)

Description: Block cipher and AES finalist.

Key: 128, 192, 256 bits.

Iv: 128 bits.

Uses: General propuse, alternative to AES.

### CAST-256

[spec](http://www.quadibloc.com/crypto/co040410.htm)

Description: Block cipher and AES finalist.

Key: 256 bits.

Iv: 128 bits.

Uses: General propuse, alternative to AES.

### Camellia

[spec](https://info.isl.ntt.co.jp/crypt/eng/camellia/)

Description: Block cipher, The cipher has been approved for use by the ISO/IEC, the European Union's NESSIE project, the Japanese CRYPTREC.

Key: 128, 192, 256 bits.

Iv: 128 bits.

Uses: General propuse, alternative to AES.

### Speck128

[spec](https://eprint.iacr.org/2013/404.pdf)

Key: 128, 192, 256 bits.

Iv: 128 bits.

Uses: IoT

### Simeck64

[spec](https://eprint.iacr.org/2015/612.pdf)

Key: 128 bits.

Iv: 64 bits.

Uses: IoT

## Modes of Operation

[Modes of Operation video](https://www.youtube.com/watch?v=4FBgb2uobWI\&list=PL6N5qY2nvvJE8X75VkXglSrVhLv1tVcfy\&index=9)

### CTR

[spec](ps://en.wikipedia.org/wiki/Block_cipher_mode_of_operation)

Description: Block cipher mode

Uses: Performance is important.

### GCM

[spec](https://en.wikipedia.org/wiki/Galois/Counter_Mode)

Description: Block cipher mode

Uses: Authenticated encryption.

* It only support *"type":"string"*
* It doesn't support *"algorithm":"SIMECK64"*

## How to ???

```python
#!/usr/bin/env python

import requests
import json
import os,binascii

def sending(message):
    url = 'http://127.0.0.1:6613/'
    response = requests.post(url, data=message)
    print response.content
    return response.content

def stream(data_js):
    req=json.loads(data_js)
    print "Enc \n " + json.dumps(req) +"\n"
    data_js_n=sending(json.dumps(req))
    answ=json.loads(data_js_n)
    print "Recived enc: \n" + (json.dumps(answ)) +"\n\n\n"
    dec='{"algorithm":"AES","plaintext":"","iv":"b05691ef92cb9c9bb05691ef92cb9c9b",\
    "version":1,"key":"b05691ef92cb9c9bb05691ef92cb9c9b","operation":"dec","type":"string", "mode":"ctr"}'
    req=json.loads(dec)
    req["plaintext"]=answ["result"]
    print "Dec \n " + json.dumps(req) +"\n"
    data_js_n=sending(json.dumps(req))
    answ2=json.loads(data_js_n)
    print "Recived dec: \n" + (json.dumps(answ2)) +"\n\n\n"


data_js='{ "version": 1 , "algorithm":"AES" , "type":"string", "plaintext": "Hello world!", "hex": 0,"operation":"enc",\
"key":"b05691ef92cb9c9bb05691ef92cb9c9b","iv":"b05691ef92cb9c9bb05691ef92cb9c9b", "mode":"ctr" }'
stream(data_js)
```

In this example we encrypt and decrypt Hello world! string using AES with the key and iv given in CTR mode.

On data*js\["algorithm"] can be one of* {AES, RC6, MARS, Twofish, SERPENT, CAST256, CAMELLIA, SPECK128, SIMECK64 }\_

```python
#!/usr/bin/env python

import socket
import json
import os,binascii

def sending(message):
    ip = '127.0.0.1'
    port = 6613
    BUFFER_SIZE = 65536
    s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
    s.connect((ip, port))
    s.send(message)
    data = s.recv(BUFFER_SIZE)
    s.close()
    return data

def stream(data_js):
    req=json.loads(data_js)
    print "Enc \n " + json.dumps(req) +"\n"
    data_js_n=sending(json.dumps(req))
    answ=json.loads(data_js_n)
    print "Recived enc: \n" + (json.dumps(answ)) +"\n\n\n"
    dec='{"algorithm":"AES","plaintext":"","iv":"b05691ef92cb9c9bb05691ef92cb9c9b",\
    "version":1,"key":"b05691ef92cb9c9bb05691ef92cb9c9b","operation":"dec","type":"string", "mode":"gcm" ,"adata":"ABCD"}'
    req=json.loads(dec)
    req["plaintext"]=answ["result"]
    print "Dec \n " + json.dumps(req) +"\n"
    data_js_n=sending(json.dumps(req))
    answ2=json.loads(data_js_n)
    print "Recived dec: \n" + (json.dumps(answ2)) +"\n\n\n"


data_js='{ "version": 1 , "algorithm":"AES" , "type":"string", "plaintext": "Hello world!", "hex": 0,"operation":"enc",\
"key":"b05691ef92cb9c9bb05691ef92cb9c9b","iv":"b05691ef92cb9c9bb05691ef92cb9c9b", "mode":"gcm" ,"adata":"ABCD"}'
stream(data_js)
```

In this example we encrypt and decrypt Hello world! string using AES with the key,iv,adata given in GCM mode.

On data*js\["algorithm"] can be one of* {AES, RC6, MARS, Twofish, SERPENT, CAST256, CAMELLIA, SPECK128}\_

Json to enc string (key and iv depends on algorithm you chose) in CTR mode

```javascript
{ "version": 1 , "algorithm":"block flavor" , "type":"string", "plaintext": "your string", "hex":BOOL,
"operation":"enc", "key":"Hex stringsize=32-64","iv":"Hex stringsize=16-32", "mode":"ctr"}
```

Json to dec string (key and iv depends on algorithm you chose) in CTR mode

```javascript
{ "version": 1 , "algorithm":"block flavor" , "type":"string", "plaintext": "your hex enc string ", 
"operation":"dec", "key":"Hex stringsize=32-64","iv":"Hex stringsize=16-32", "mode":"ctr"}
```

* To enc/dec a file you need to change *"type":"string" -> "type":"file" , "plaintext": "your hex enc string " -> "file":"your file"*
* To use enc/dec GCM mode you need to change *"mode":"ctr"->"mode":"gcm"* , add *"adata":"your string"* and *"hex"* parameters
* *"hex"* parameter apply for *"string"* and *"adata"* parameter


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