Standards¶
Cryptography¶
Hashes¶
All hashes use the SHA256 algorithm as defined in FIPS 180-4. The reference implementation uses the sha256 package from golang’s standard library.
Example¶
The SHA256 hash of the message “Hello World!” results in:
0x7f83b1657ff1fc53b92dc18148a1d65dfc2d4b1fa3d677284addd200126d9069
Signatures¶
All signatures use EdDSA with Curve25519. The reference implementation uses the go-libsodium library.
Example¶
Given the following keypair:
0x75a8c71c874456844313e4e0766d9aee0b225a95497b576f0c914a19ce1c5f96 // private
0xbe725676384aa8b7ce1faf7a0c20b7cb3e862c139bc0a9479a8789346e4af234 // public
Signing the msg “Hello World!” with the given private key would result in the following signature.
0xa4a0e361cfb0a28c8f577fe6ba440d8e4a441d42a1d93b695cdd470d14ced778adb70a8e1762f42366235610cebd98e58f791fae11faa7342077c330fe5bc707
Encoding¶
Some networking data is encoded using RLP to allow for more efficient usage of bandwidth.
Recursive Length Prefix (RLP)¶
Recursive Length Prefix (RLP) is a serialization format originally created by the Ethereum developers. Unlike other binary serialization formats, RLP doesn’t differentiate between different data types but only encodes data structure.
Definition¶
- Single bytes between 0x00 and 0x7f are their own RLP encoding.
- Byte arrays with a length of 0 to 55 bytes are encoded using a special prefix of 0x80 plus the length of the array.
Note
Special case: Single bytes between 0x80 and 0xff are encoded as a byte array of length 1 and are thus prefixed with 0x81.
- Byte arrays larger than 55 bytes are encoded using two prefixes. The first prefix pf1 defines how many bytes are going to be used to encode the length of the array. The second prefix pf2 defines the length of the array. pf1 is calculated by adding the length of pf2 to 0xb7. pf2 is simply the length of the byte array and might be several bytes long.
- Lists of length 0 to 55 are prefixed with 0xc0 added to the length of the list in bytes. List items can be any other RLP encoded data (lists, byte arrays, bytes).
- List of length greater than 55 are similarly encoded using two prefixes. The first prefix pf1 defines how many bytes are going to be used to encode the length of the list. The second prefix pf2 defines the length of the list. pf1 is calculated by adding the length of pf2 to 0xf7. pf2 is simply the length of the list in bytes and might be several bytes long.
Note
The first byte of the RLP encoding thus implies the data structure as follows:
| Byte range | Data structure |
|---|---|
| [0x00, 0x7f] | Single byte |
| [0x80, 0xb7] | Byte array of size 0-55 |
| [0xb8, 0xbf] | Byte array of size > 55 |
| [0xc0, 0xf7] | List of size 0-55 |
| [0xf8, 0xff] | List of size > 55 |
Examples¶
| Data | RLP Encoding |
|---|---|
| 0x05 | [0x05] |
| “H” | [0x68] |
| “Hello” | [0x85, 0x68, 0x65, 0x6c, 0x6c, 0x6f] |
| “World” | [0x85, 0x77 0x6f 0x72 0x6c 0x64] |
| [“Hello”,”World”] | [0xcc, 0x85, 0x68, 0x65, 0x6c, 0x6c, 0x6f, 0x85, 0x77 0x6f 0x72 0x6c 0x64] |
| [[], [[]], [[], [[]]]] | [ 0xc7, 0xc0, 0xc1, 0xc0, 0xc3, 0xc0, 0xc1, 0xc0 ] |
Note
Since RLP doesn’t know any data types, examples encode strings using ASCII for simplicity.
Decimals¶
The value of SonoCoin is represented by a 64 bit unsigned integer (uint64). In order to allow fractions of a SonoCoin to be transfered, a constant is defined that determines how many decimal places are included in the value.
SonoCoin uses 8 decimal places, meaning that the amount of SonoCoins is the uint64 value divided by 
.
Examples¶
| uint64 Value | SonoCoin |
|---|---|
| 1 | 0.00000001 |
| 10 | 0.0000001 |
| 100 | 0.000001 |
| 1000 | 0.00001 |
| 10000 | 0.0001 |
| 100000 | 0.001 |
| 1000000 | 0.01 |
| 10000000 | 0.1 |
| 100000000 | 1 |
| 1000000000 | 10 |
| 10000000000 | 100 |
| 100000000000 | 1000 |
| 1000000000000 | 10000 |
| 10000000000000 | 100000 |
| 100000000000000 | 1000000 |
| 1000000000000000 | 10000000 |
| 10000000000000000 | 100000000 |