Diffie-Hellman—A public-key cryptography protocol that allows two parties to establish a shared secret over an unsecure communications channel. Diffie-Hellman is used within IKE to establish session keys. It supports 768-bit (the default), 1024-bit, 1536-bit, 2048-bit, 3072-bit, and 4096-bit DH groups. Mar 25, 2008 A simple explanation that I came across is that you should image a trunk with two padlocks on it. These padlocks have different keys that each party carries with them: the trunk may only be opened once both keys have been obtained. This article presents a C# implementation of the Diffie-Hellman algorithm. May 20, 2016 Diffie-Hellman works by calculating a shared secret based on our private key and the other party’s public key, so this is all we need in this case. The magic of DH is that each party will calculate the same value despite having different sets of keys available to them.
-->Definition
Provides a Cryptography Next Generation (CNG) implementation of the Elliptic Curve Diffie-Hellman (ECDH) algorithm. This class is used to perform cryptographic operations.
- I'm trying to implement a diffie-hellman key exchange. Let's say I found a large prime number p - how can I find a generator g? Restricted by the multiprecision library that I have to use, only a few basic operations (+,., -, /, pow, modExp, modMult, mod, gcd, isPrime, genRandomPrime, genRandomBits, and a few more) are available.
- Diffie–Hellman key exchange is a method of securely exchanging cryptographic keys over a public channel and was one of the first public-key protocols as conceived by Ralph Merkle and named after Whitfield Diffie and Martin Hellman.
Examples
The following example shows how to use the ECDiffieHellmanCng class to establish a key exchange and how to use that key to encrypt a message that can be sent over a public channel and decrypted by the receiver.
Remarks
The ECDiffieHellmanCng class enables two parties to exchange private key material even if they are communicating through a public channel. Both parties can calculate the same secret value, which is referred to as the secret agreement in the managed Diffie-Hellman classes. The secret agreement can then be used for a variety of purposes, including as a symmetric key. However, instead of exposing the secret agreement directly, the ECDiffieHellmanCng class does some post-processing on the agreement before providing the value. This post processing is referred to as the key derivation function (KDF); you can select which KDF you want to use and set its parameters through a set of properties on the instance of the Diffie-Hellman object.
| Key derivation function | Properties |
|---|---|
| Hash | HashAlgorithm - The hash algorithm that is used to process the secret agreement. SecretPrepend - An optional byte array to prepend to the secret agreement before hashing it. SecretAppend - An optional byte array to append to the secret agreement before hashing it. |
| Hmac | HashAlgorithm - The hash algorithm that is used to process the secret agreement. SecretPrepend- An optional byte array to prepend to the secret agreement before hashing it. SecretAppend - An optional byte array to append to the secret agreement before hashing it. |
| Tls | Label - The label for key derivation. Seed - The seed for key derivation. |
Diffie Hellman Group
The result of passing the secret agreement through the key derivation function is a byte array that may be used as key material for your application. The number of bytes of key material generated is dependent on the key derivation function; for example, SHA-256 will generate 256 bits of key material, whereas SHA-512 will generate 512 bits of key material.The basic flow of an ECDH key exchange is as follows:
Alice and Bob create a key pair to use for the Diffie-Hellman key exchange operation
Alice and Bob configure the KDF using parameters the agree on.
Alice sends Bob her public key.
Bob sends Alice his public key.
Alice and Bob use each other's public keys to generate the secret agreement, and apply the KDF to the secret agreement to generate key material.
Constructors
| ECDiffieHellmanCng() | Initializes a new instance of the ECDiffieHellmanCng class with a random key pair. |
| ECDiffieHellmanCng(CngKey) | Initializes a new instance of the ECDiffieHellmanCng class by using the specified CngKey object. |
| ECDiffieHellmanCng(ECCurve) | Creates a new instance of the ECDiffieHellmanCng class whose public/private key pair is generated over the specified curve. |
| ECDiffieHellmanCng(Int32) | Initializes a new instance of the ECDiffieHellmanCng class with a random key pair, using the specified key size. |
Fields
| KeySizeValue | Represents the size, in bits, of the key modulus used by the asymmetric algorithm. (Inherited from AsymmetricAlgorithm) |
| LegalKeySizesValue | Specifies the key sizes that are supported by the asymmetric algorithm. (Inherited from AsymmetricAlgorithm) |
Properties
| HashAlgorithm | Gets or sets the hash algorithm to use when generating key material. |
| HmacKey | Gets or sets the Hash-based Message Authentication Code (HMAC) key to use when deriving key material. |
| Key | Specifies the CngKey that is used by the current object for cryptographic operations. |
| KeyDerivationFunction | Gets or sets the key derivation function for the ECDiffieHellmanCng class. |
| KeyExchangeAlgorithm | Gets the name of the key exchange algorithm. (Inherited from ECDiffieHellman) |
| KeySize | Gets or sets the size, in bits, of the key modulus used by the asymmetric algorithm. Mar 07, 2013 Extra Tags IGNORE avatar the last airbender the game, avatar game online, avatar pc game, avatar maker game, james cameron's avatar, avatar creator game, avatar airbender game, create avatar game, avatar the game download for free, avatar the game download demo, avatar the pc game rar download, avatar the game crack, avatar the game serial, avatar the game keygen, Avatar The Game. Avatar the game on pc. |
| Label | Gets or sets the label value that is used for key derivation. |
| LegalKeySizes | Gets the key sizes that are supported by the asymmetric algorithm. (Inherited from AsymmetricAlgorithm) |
| PublicKey | Gets the public key that can be used by another ECDiffieHellmanCng object to generate a shared secret agreement. |
| SecretAppend | Gets or sets a value that will be appended to the secret agreement when generating key material. |
| SecretPrepend | Gets or sets a value that will be added to the beginning of the secret agreement when deriving key material. |
| Seed | Gets or sets the seed value that will be used when deriving key material. |
| SignatureAlgorithm | Gets the name of the signature algorithm. (Inherited from ECDiffieHellman) |
| UseSecretAgreementAsHmacKey | Gets a value that indicates whether the secret agreement is used as a Hash-based Message Authentication Code (HMAC) key to derive key material. |
Methods
| Clear() | Releases all resources used by the AsymmetricAlgorithm class. (Inherited from AsymmetricAlgorithm) |
| DeriveKeyFromHash(ECDiffieHellmanPublicKey, HashAlgorithmName) | Performs key derivation using a specified hash algorithm. (Inherited from ECDiffieHellman) |
| DeriveKeyFromHash(ECDiffieHellmanPublicKey, HashAlgorithmName, Byte[], Byte[]) | Performs key derivation using a specified hash algorithm with optional prepended or appended data. |
| DeriveKeyFromHmac(ECDiffieHellmanPublicKey, HashAlgorithmName, Byte[]) | Performs key derivation using a specified HMAC (Hash-based Message Authentication Code) algorithm. (Inherited from ECDiffieHellman) |
| DeriveKeyFromHmac(ECDiffieHellmanPublicKey, HashAlgorithmName, Byte[], Byte[], Byte[]) | Performs key derivation using a specified HMAC (Hash-based Message Authentication Code) algorithm with optional prepended or appended data. |
| DeriveKeyMaterial(CngKey) | Derives the key material that is generated from the secret agreement between two parties, given a CngKey object that contains the second party's public key. |
| DeriveKeyMaterial(ECDiffieHellmanPublicKey) | Derives the key material that is generated from the secret agreement between two parties, given an ECDiffieHellmanPublicKey object that contains the second party's public key. |
| DeriveKeyTls(ECDiffieHellmanPublicKey, Byte[], Byte[]) | Performs key derivation using the TLS (Transport Layer Security) 1.1 PRF (Pseudo-Random Function). |
| DeriveSecretAgreementHandle(CngKey) | Gets a handle to the secret agreement generated between two parties, given a CngKey object that contains the second party's public key. |
| DeriveSecretAgreementHandle(ECDiffieHellmanPublicKey) | Gets a handle to the secret agreement generated between two parties, given an ECDiffieHellmanPublicKey object that contains the second party's public key. |
| Dispose() | Releases all resources used by the current instance of the AsymmetricAlgorithm class. (Inherited from AsymmetricAlgorithm) |
| Dispose(Boolean) | Releases the unmanaged resources used by the AsymmetricAlgorithm class and optionally releases the managed resources. (Inherited from AsymmetricAlgorithm) |
| Equals(Object) | Determines whether the specified object is equal to the current object. (Inherited from Object) |
| ExportECPrivateKey() | Exports the current key in the ECPrivateKey format. (Inherited from ECDiffieHellman) |
| ExportEncryptedPkcs8PrivateKey(ReadOnlySpan<Byte>, PbeParameters) | Exports the current key in the PKCS#8 EncryptedPrivateKeyInfo format with a byte-based password. (Inherited from AsymmetricAlgorithm) |
| ExportEncryptedPkcs8PrivateKey(ReadOnlySpan<Char>, PbeParameters) | Exports the current key in the PKCS#8 EncryptedPrivateKeyInfo format with a char-based password. (Inherited from AsymmetricAlgorithm) |
| ExportExplicitParameters(Boolean) | Exports the key and explicit curve parameters used by the ECCurve object into an ECParameters object. |
| ExportParameters(Boolean) | Exports the key used by the ECCurve object into an ECParameters object. |
| ExportPkcs8PrivateKey() | Exports the current key in the PKCS#8 PrivateKeyInfo format. (Inherited from AsymmetricAlgorithm) |
| ExportSubjectPublicKeyInfo() | Exports the public-key portion of the current key in the X.509 SubjectPublicKeyInfo format. (Inherited from AsymmetricAlgorithm) |
| FromXmlString(String) | This method is not implemented. Call of duty advanced warfare key code generator download. About Call of Duty Advanced Warfare Keygen 2015. We are extremely happy that we can share it with you. We worked on this tool really hard, so in return we expect you to appreciate our work.All that you need to do to get your free cd key is to download our keygen tool “Call of Duty Advanced Warfare CD Key Generator” and run it. May 08, 2017 Thanks to this fantastic Call of Duty: Advanced Warfare Generator you can generate different Keys for you and your friends!The only Call of Duty: Advanced Warfare code generator that works.No download required.We just released a new leaked Call of Duty: Advanced Warfare Serial Key Generator that can generate keys for Windows PC, Xbox One. Sep 15, 2018 Generate 100% working and legit keys using the latest Call of Duty Advanced Warfare Keygen and install the game without spending a single dime for it. Behold everyone, the key generator you all have been waiting for is here. This is the answer for those who are Call of Duty fans but are bombarded with the financial. Call of Duty Advanced Warfare CD Key Generator. Call of Duty Advanced Warfare has caused a lot of tension from how anticipated it is. Now that an official release date has been given to the public, millions of fans are looking for Call of Duty Advanced Warfare CD key generators in order to play Call of Duty Advanced Warfare CD Key for free. Jun 11, 2014 Call of Duty Advanced Warfare Key Generator Screenshot. We present to you the new and updated Call of Duty Advanced Warfare Key Generator. The Key Generator is simple, 100% clean and safe, virus free, works smoothly without any problems at all, updated weekly, all the keys are valid and unique. |
| FromXmlString(String, ECKeyXmlFormat) | Deserializes the key information from an XML string by using the specified format. |
| GenerateKey(ECCurve) | Generates a new ephemeral public/private key pair for the specified curve. |
| GetHashCode() | Serves as the default hash function. (Inherited from Object) |
| GetType() | Gets the Type of the current instance. (Inherited from Object) |
| ImportECPrivateKey(ReadOnlySpan<Byte>, Int32) | Imports the public/private keypair from an ECPrivateKey structure, replacing the keys for this object. (Inherited from ECDiffieHellman) |
| ImportEncryptedPkcs8PrivateKey(ReadOnlySpan<Byte>, ReadOnlySpan<Byte>, Int32) | Imports the public/private keypair from a PKCS#8 EncryptedPrivateKeyInfo structure after decrypting with a byte-based password, replacing the keys for this object. (Inherited from ECDiffieHellman) |
| ImportEncryptedPkcs8PrivateKey(ReadOnlySpan<Char>, ReadOnlySpan<Byte>, Int32) | Imports the public/private keypair from a PKCS#8 EncryptedPrivateKeyInfo structure after decrypting with a char-based password, replacing the keys for this object. (Inherited from ECDiffieHellman) |
| ImportParameters(ECParameters) | Imports the specified parameters for an ECCurve object as a key into the current instance. |
| ImportPkcs8PrivateKey(ReadOnlySpan<Byte>, Int32) | Imports the public/private keypair from a PKCS#8 PrivateKeyInfo structure after decryption, replacing the keys for this object. (Inherited from ECDiffieHellman) |
| ImportSubjectPublicKeyInfo(ReadOnlySpan<Byte>, Int32) | Imports the public key from an X.509 SubjectPublicKeyInfo structure after decryption, replacing the keys for this object. (Inherited from ECDiffieHellman) |
| MemberwiseClone() | Creates a shallow copy of the current Object. (Inherited from Object) |
| ToString() | Returns a string that represents the current object. (Inherited from Object) |
| ToXmlString(Boolean) | This method is not implemented. |
| ToXmlString(ECKeyXmlFormat) | Serializes the key information to an XML string by using the specified format. |
| TryExportECPrivateKey(Span<Byte>, Int32) | Attempts to export the current key in the ECPrivateKey format into a provided buffer. (Inherited from ECDiffieHellman) |
| TryExportEncryptedPkcs8PrivateKey(ReadOnlySpan<Byte>, PbeParameters, Span<Byte>, Int32) | Attempts to export the current key in the PKCS#8 EncryptedPrivateKeyInfo format into a provided buffer, using a byte-based password. (Inherited from ECDiffieHellman) |
| TryExportEncryptedPkcs8PrivateKey(ReadOnlySpan<Char>, PbeParameters, Span<Byte>, Int32) | Attempts to export the current key in the PKCS#8 EncryptedPrivateKeyInfo format into a provided buffer, using a char-based password. (Inherited from ECDiffieHellman) |
| TryExportPkcs8PrivateKey(Span<Byte>, Int32) | Attempts to export the current key in the PKCS#8 PrivateKeyInfo format into a provided buffer. (Inherited from ECDiffieHellman) |
| TryExportSubjectPublicKeyInfo(Span<Byte>, Int32) | Attempts to export the current key in the X.509 SubjectPublicKeyInfo format into a provided buffer. (Inherited from ECDiffieHellman) |
Explicit Interface Implementations
| IDisposable.Dispose() | For a description of this member, see Dispose(). (Inherited from AsymmetricAlgorithm) |