Package org.bouncycastle.pqc.crypto.ntru

## Class NTRUEncryptionParameters

- java.lang.Object
- - org.bouncycastle.pqc.crypto.ntru.NTRUEncryptionParameters

- All Implemented Interfaces:
    `java.lang.Cloneable`

      public class NTRUEncryptionParameters
      extends java.lang.Object
      implements java.lang.Cloneable

  A set of parameters for NtruEncrypt. Several predefined parameter sets are available and new ones can be created as well.

- - ### Field Summary

    Fields
    Modifier and Type | Field | Description
    --- | --- | ---
    `int` | `bufferLenBits` |
    `int` | `c` |
    `int` | `db` |
    `int` | `df` |
    `int` | `df1` |
    `int` | `df2` |
    `int` | `df3` |
    `int` | `dg` |
    `int` | `dm0` |
    `int` | `dr` |
    `int` | `dr1` |
    `int` | `dr2` |
    `int` | `dr3` |
    `boolean` | `fastFp` |
    `Digest` | `hashAlg` |
    `boolean` | `hashSeed` |
    `int` | `maxMsgLenBytes` |
    `int` | `minCallsMask` |
    `int` | `minCallsR` |
    `int` | `N` |
    `byte[]` | `oid` |
    `int` | `pkLen` |
    `int` | `polyType` |
    `int` | `q` |
    `boolean` | `sparse` |

  - ### Constructor Summary

    Constructors
    Constructor | Description
    --- | ---
    `NTRUEncryptionParameters​(int N, int q, int df, int dm0, int db, int c, int minCallsR, int minCallsMask, boolean hashSeed, byte[] oid, boolean sparse, boolean fastFp, Digest hashAlg)` | Constructs a parameter set that uses ternary private keys (i.e.
    `NTRUEncryptionParameters​(int N, int q, int df1, int df2, int df3, int dm0, int db, int c, int minCallsR, int minCallsMask, boolean hashSeed, byte[] oid, boolean sparse, boolean fastFp, Digest hashAlg)` | Constructs a parameter set that uses product-form private keys (i.e.
    `NTRUEncryptionParameters​(java.io.InputStream is)` | Reads a parameter set from an input stream.

  - ### Method Summary

    All Methods Instance Methods Concrete Methods
    Modifier and Type | Method | Description
    --- | --- | ---
    `NTRUEncryptionParameters` | `clone()` |
    `boolean` | `equals​(java.lang.Object obj)` |
    `int` | `getMaxMessageLength()` | Returns the maximum length a plaintext message can be with this parameter set.
    `int` | `hashCode()` |
    `java.lang.String` | `toString()` |
    `void` | `writeTo​(java.io.OutputStream os)` | Writes the parameter set to an output stream

    - ### Methods inherited from class java.lang.Object

      `finalize, getClass, notify, notifyAll, wait, wait, wait`

- - ### Field Detail

    - #### N

          public int N

    - #### q

          public int q

    - #### df

          public int df

    - #### df1

          public int df1

    - #### df2

          public int df2

    - #### df3

          public int df3

    - #### dr

          public int dr

    - #### dr1

          public int dr1

    - #### dr2

          public int dr2

    - #### dr3

          public int dr3

    - #### dg

          public int dg

    - #### maxMsgLenBytes

          public int maxMsgLenBytes

    - #### db

          public int db

    - #### bufferLenBits

          public int bufferLenBits

    - #### dm0

          public int dm0

    - #### pkLen

          public int pkLen

    - #### c

          public int c

    - #### minCallsR

          public int minCallsR

    - #### minCallsMask

          public int minCallsMask

    - #### hashSeed

          public boolean hashSeed

    - #### oid

          public byte[] oid

    - #### sparse

          public boolean sparse

    - #### fastFp

          public boolean fastFp

    - #### polyType

          public int polyType

    - #### hashAlg

          public Digest hashAlg

  - ### Constructor Detail

    - #### NTRUEncryptionParameters

          public NTRUEncryptionParameters​(int N,
                                          int q,
                                          int df,
                                          int dm0,
                                          int db,
                                          int c,
                                          int minCallsR,
                                          int minCallsMask,
                                          boolean hashSeed,
                                          byte[] oid,
                                          boolean sparse,
                                          boolean fastFp,
                                          Digest hashAlg)

      Constructs a parameter set that uses ternary private keys (i.e. `polyType=SIMPLE`).
      Parameters:
        `N` - number of polynomial coefficients
        `q` - modulus
        `df` - number of ones in the private polynomial `f`
        `dm0` - minimum acceptable number of -1's, 0's, and 1's in the polynomial `m'` in the last encryption step
        `db` - number of random bits to prepend to the message
        `c` - a parameter for the Index Generation Function (`IndexGenerator`)
        `minCallsR` - minimum number of hash calls for the IGF to make
        `minCallsMask` - minimum number of calls to generate the masking polynomial
        `hashSeed` - whether to hash the seed in the MGF first (true) or use the seed directly (false)
        `oid` - three bytes that uniquely identify the parameter set
        `sparse` - whether to treat ternary polynomials as sparsely populated (`SparseTernaryPolynomial` vs `DenseTernaryPolynomial`)
        `fastFp` - whether `f=1+p*F` for a ternary `F` (true) or `f` is ternary (false)
        `hashAlg` - a valid identifier for a `java.security.MessageDigest` instance such as `SHA-256`. The `MessageDigest` must support the `getDigestLength()` method.

    - #### NTRUEncryptionParameters

          public NTRUEncryptionParameters​(int N,
                                          int q,
                                          int df1,
                                          int df2,
                                          int df3,
                                          int dm0,
                                          int db,
                                          int c,
                                          int minCallsR,
                                          int minCallsMask,
                                          boolean hashSeed,
                                          byte[] oid,
                                          boolean sparse,
                                          boolean fastFp,
                                          Digest hashAlg)

      Constructs a parameter set that uses product-form private keys (i.e. `polyType=PRODUCT`).
      Parameters:
        `N` - number of polynomial coefficients
        `q` - modulus
        `df1` - number of ones in the private polynomial `f1`
        `df2` - number of ones in the private polynomial `f2`
        `df3` - number of ones in the private polynomial `f3`
        `dm0` - minimum acceptable number of -1's, 0's, and 1's in the polynomial `m'` in the last encryption step
        `db` - number of random bits to prepend to the message
        `c` - a parameter for the Index Generation Function (`IndexGenerator`)
        `minCallsR` - minimum number of hash calls for the IGF to make
        `minCallsMask` - minimum number of calls to generate the masking polynomial
        `hashSeed` - whether to hash the seed in the MGF first (true) or use the seed directly (false)
        `oid` - three bytes that uniquely identify the parameter set
        `sparse` - whether to treat ternary polynomials as sparsely populated (`SparseTernaryPolynomial` vs `DenseTernaryPolynomial`)
        `fastFp` - whether `f=1+p*F` for a ternary `F` (true) or `f` is ternary (false)
        `hashAlg` - a valid identifier for a `java.security.MessageDigest` instance such as `SHA-256`

    - #### NTRUEncryptionParameters

          public NTRUEncryptionParameters​(java.io.InputStream is)
                                   throws java.io.IOException

      Reads a parameter set from an input stream.
      Parameters:
        `is` - an input stream
      Throws:
        `java.io.IOException`

  - ### Method Detail

    - #### clone

          public NTRUEncryptionParameters clone()

      Overrides:
        `clone` in class `java.lang.Object`

    - #### getMaxMessageLength

          public int getMaxMessageLength()

      Returns the maximum length a plaintext message can be with this parameter set.
      Returns:
        the maximum length in bytes

    - #### writeTo

          public void writeTo​(java.io.OutputStream os)
                       throws java.io.IOException

      Writes the parameter set to an output stream
      Parameters:
        `os` - an output stream
      Throws:
        `java.io.IOException`

    - #### hashCode

          public int hashCode()

      Overrides:
        `hashCode` in class `java.lang.Object`

    - #### equals

          public boolean equals​(java.lang.Object obj)

      Overrides:
        `equals` in class `java.lang.Object`

    - #### toString

          public java.lang.String toString()

      Overrides:
        `toString` in class `java.lang.Object`