1 files changed, 104 insertions, 3 deletions

diff --git a/ffi/cs/readme.md b/ffi/cs/readme.md
index 70e87c1..456dc0c 100644
--- a/ffi/cs/readme.md
+++ b/ffi/cs/readme.md
@@ -1,4 +1,4 @@
-# BLS threshold signature for C#
+# C# binding of BLS threshold signature library
 
 # Installation Requirements
 
@@ -18,8 +18,109 @@ cd bls
 mklib dll
 ```
 
-# Remark
-bls256 is obsolete. Please use bls.sln.
+# How to build a sample
+
+Open bls/ffi/cs/bls.sln and exec it.
+
+* Remark. bls256 is obsolete. Please use bls.sln.
+
+# class and API
+
+## API
+
+* `Init(int curveType = BN254);`
+    * initialize this library with a curve `curveType`.
+    * curveType = BN254 or BLS12_381
+* `SecretKey ShareSecretKey(in SecretKey[] msk, in Id id);`
+    * generate the shared secret key from a sequence of master secret keys msk and Id.
+* `SecretKey RecoverSecretKey(in SecretKey[] secVec, in Id[] idVec);`
+    * recover the secret key from a sequence of secret keys secVec and idVec.
+* `PublicKey SharePublicKey(in PublicKey[] mpk, in Id id);`
+    * generate the shared public key from a sequence of master public keys mpk and Id.
+* `PublicKey RecoverPublicKey(in PublicKey[] pubVec, in Id[] idVec);`
+    * recover the public key from a sequence of public keys pubVec and idVec.
+* `Signature RecoverSign(in Signature[] sigVec, in Id[] idVec);`
+    * recover the signature from a sequence of signatures siVec and idVec.
+
+## Id
+
+Identifier class
+
+* `byte[] Serialize();`
+    * serialize Id
+* `void Deserialize(byte[] buf);`
+    * deserialize from byte[] buf
+* `bool IsEqual(in Id rhs);`
+    * equality
+* `void SetDecStr(string s);`
+    * set by a decimal string s
+* `void SetHexStr(string s);`
+    * set by a hexadecimal string s
+* `void SetInt(int x);`
+    * set an integer x
+* `string GetDecStr();`
+    * get a decimal string
+* `string GetHexStr();`
+    * get a hexadecimal string
+
+## SecretKey
+
+* `byte[] Serialize();`
+    * serialize SecretKey
+* `void Deserialize(byte[] buf);`
+    * deserialize from byte[] buf
+* `bool IsEqual(in SecretKey rhs);`
+    * equality
+* `string GetDecStr();`
+    * get a decimal string
+* `string GetHexStr();`
+    * get a hexadecimal string
+* `void Add(in SecretKey rhs);`
+    * add a secret key rhs
+* `void SetByCSPRNG();`
+    * set a secret key by cryptographically secure pseudo random number generator
+* `void SetHashOf(string s);`
+    * set a secret key by a hash of string s
+* `PublicKey GetPublicKey();`
+    * get the corresponding public key to a secret key
+* `Signature Sign(string m);`
+    * sign a string m
+* `Signature GetPop();`
+    * get a PoP (Proof Of Posession) for a secret key
+
+## PublicKey
+
+* `byte[] Serialize();`
+    * serialize PublicKey
+* `void Deserialize(byte[] buf);`
+    * deserialize from byte[] buf
+* `bool IsEqual(in PublicKey rhs);`
+    * equality
+* `void Add(in PublicKey rhs);`
+    * add a public key rhs
+* `string GetDecStr();`
+    * get a decimal string
+* `string GetHexStr();`
+    * get a hexadecimal string
+* `bool Verify(in Signature sig, string m);`
+    * verify the validness of the sig with m
+* `bool VerifyPop(in Signature pop);`
+    * verify the validness of PoP
+
+## Signature
+
+* `byte[] Serialize();`
+    * serialize Signature
+* `void Deserialize(byte[] buf);`
+    * deserialize from byte[] buf
+* `bool IsEqual(in Signature rhs);`
+    * equality
+* `void Add(in Signature rhs);`
+    * add a signature key rhs
+* `string GetDecStr();`
+    * get a decimal string
+* `string GetHexStr();`
+    * get a hexadecimal string
 
 # License