Class HashCash

Method Details

• mintCash

  public static HashCash mintCash​(String resource, int value) throws NoSuchAlgorithmException

  Mints a version 1 HashCash using now as the date

  Parameters:

  resource - the string to be encoded in the HashCash

  Throws:

  NoSuchAlgorithmException - If SHA1 is not a supported Message Digest

• mintCash

  public static HashCash mintCash​(String resource, int value, int version) throws NoSuchAlgorithmException

  Mints a HashCash using now as the date

  Parameters:

  resource - the string to be encoded in the HashCash

  version - Which version to mint. Only valid values are 0 and 1

  Throws:

  NoSuchAlgorithmException - If SHA1 is not a supported Message Digest

• mintCash

  public static HashCash mintCash​(String resource, Calendar date, int value) throws NoSuchAlgorithmException

  Mints a version 1 HashCash

  Parameters:

  resource - the string to be encoded in the HashCash

  Throws:

  NoSuchAlgorithmException - If SHA1 is not a supported Message Digest

• mintCash

  public static HashCash mintCash​(String resource, Calendar date, int value, int version) throws NoSuchAlgorithmException

  Mints a HashCash

  Parameters:

  resource - the string to be encoded in the HashCash

  version - Which version to mint. Only valid values are 0 and 1

  Throws:

  NoSuchAlgorithmException - If SHA1 is not a supported Message Digest

• mintCash

  public static HashCash mintCash​(String resource, Map<String,​List<String>> extensions, int value) throws NoSuchAlgorithmException

  Mints a version 1 HashCash using now as the date

  Parameters:

  resource - the string to be encoded in the HashCash

  extensions - Extra data to be encoded in the HashCash

  Throws:

  NoSuchAlgorithmException - If SHA1 is not a supported Message Digest

• mintCash

  public static HashCash mintCash​(String resource, Map<String,​List<String>> extensions, int value, int version) throws NoSuchAlgorithmException

  Mints a HashCash using now as the date

  Parameters:

  resource - the string to be encoded in the HashCash

  extensions - Extra data to be encoded in the HashCash

  version - Which version to mint. Only valid values are 0 and 1

  Throws:

  NoSuchAlgorithmException - If SHA1 is not a supported Message Digest

• mintCash

  public static HashCash mintCash​(String resource, Map<String,​List<String>> extensions, Calendar date, int value) throws NoSuchAlgorithmException

  Mints a version 1 HashCash

  Parameters:

  resource - the string to be encoded in the HashCash

  extensions - Extra data to be encoded in the HashCash

  Throws:

  NoSuchAlgorithmException - If SHA1 is not a supported Message Digest

• mintCash

  public static HashCash mintCash​(String resource, Map<String,​List<String>> extensions, Calendar date, int value, int version) throws NoSuchAlgorithmException

  Mints a HashCash

  Parameters:

  resource - the string to be encoded in the HashCash

  extensions - Extra data to be encoded in the HashCash

  version - Which version to mint. Only valid values are 0 and 1

  Throws:

  NoSuchAlgorithmException - If SHA1 is not a supported Message Digest

• equals

  public boolean equals​(Object obj)

  Two objects are considered equal if they are both of type HashCash and have an identical string representation

  Overrides:

  equals in class Object

• hashCode

  public int hashCode()

  Implemented based on definition of equals()

  Overrides:

  hashCode in class Object

• toString

  public String toString()

  Returns the canonical string representation of the HashCash

  Overrides:

  toString in class Object

• getExtensions

  public Map<String,​List<String>> getExtensions()

  Extra data encoded in the HashCash

• getResource

  public String getResource()

  The primary resource being protected

• getDate

  public Calendar getDate()

  The minting date

• getValue

  public int getValue()

  The value of the HashCash (e.g. how many leading zero bits it has)

• getVersion

  public int getVersion()

  Which version of HashCash is used here

• estimateTime

  public static long estimateTime​(int value) throws NoSuchAlgorithmException

  Estimates how many milliseconds it would take to mint a cash of the specified value.

  • NOTE1: Minting time can vary greatly in fact, half of the time it will take half as long)
  • NOTE2: The first time that an estimation function is called it is expensive (on the order of seconds). After that, it is very quick.

  Throws:

  NoSuchAlgorithmException - If SHA1 is not a supported Message Digest

• estimateValue

  public static int estimateValue​(int secs) throws NoSuchAlgorithmException

  Estimates what value (e.g. how many bits of collision) are required for the specified length of time.

  • NOTE1: Minting time can vary greatly in fact, half of the time it will take half as long)
  • NOTE2: The first time that an estimation function is called it is expensive (on the order of seconds). After that, it is very quick.

  Throws:

  NoSuchAlgorithmException - If SHA1 is not a supported Message Digest

• compareTo

  public int compareTo​(HashCash other)

  Compares the value of two HashCashes

  Specified by:

  compareTo in interface Comparable<HashCash>

  Parameters:

  other -

  See Also:

  Comparable.compareTo(Object)