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……
string strPublicKey = crypt.ToXmlString(false);
// public key
string strPrivateKey = crypt.ToXmlString(true);
// private key
(2)Code-conversing the data
……
byte[] bytes =
Encoding.GetEncoding("GB2312").GetBytes(“plaintext”
);//importing plaintext data and symmetric key
( 3 ) Encrypting with Encrypt ( ) of RSA-
CryptoServiceProvider
……
byte[] cipherBytes = crypt.Encrypt(bytes, false);
When decrypting with this method, we only use
Decrypt () of RSACryptoServiceProvider.
C. Data Signature and the Verification
.NET Framework provides signed data and documents
with RSACryptoServiceProvider and DSACrypto-
ServiceProvider class.
That is, RSACryptoServiceProvider crypt = new
RSACryptoServiceProvider() importing one’s own
private key for signing.
The theory of singing with crypt.FromXmlString-
(strPrivateKey), as a matter of fact, is using plaintext to
get hash code and then encrypting the hash code with
one’s own private key. Based on the plaintext, we can use
SignData () to get hash code and signed data.
byte[] signBytes = crypt.SignData(bytData, offset,
count, SHA1.Create());//SHA1.Create() enable us to
obtain hash code of the data.
The data verification is accomplished by comparing
the re-generated hash with the original hash to determine
whether the data have been altered or not. After
importing counterpart’s public key, the verification
results prove that the new scheme is up to expectation by
using VerifyData(bytData, SHA1.Create(), bytSignature).
Ⅳ. CONCLUSIONS
This paper studied the two conventional computer
security technologies, digital signature and digital
envelope, based on which, a more secure scheme was
constructed. It is proved that the communication data can
meet the three indicators, confidentiality, integrity and
undeniablility. Our next step is to put the new scheme
into practical application; however, it is necessary to
point out that the .Net, as the development environment,
provides first-class encryption model and encryption
class, making the implementation of the scheme become
much easier.
REFERENCES
[1] [Wikipedia’s digital signature,]Wikipedia page: Digital
signature, last modified on 1 September 2009,
http://en.wikipedia.org/wiki/Digital_signature
[2] PKCS #7 Version 1.6 Bulletin:Cryptographic message
syntax, RSA Laboratories[S].
[3] ZHAO Yan-bo, ZHANG Xue-jie, JIANG Yong-ling.
Application researches on high strength file encryption
based on digital envelope. Computer Engineering and
Design[J].2007.9:4357-4359
[4] Gu C. X., Zhu Y. F., Zhang Y. J. A Formal Model for the
Security of Proxy Signature Schemes. Wuhan University
Journal of Natural Science, 10(1), 2005: 275-278.
[5] Ureche O, Plamondon R. Document transport, transfer and
exchange:Security and commercial aspects
[C].ICDAR.Washington,DC,USA:IEEE Computer
Society,1999:585-588.
[6] Okamoto T., Inomata A., Okamoto E. A Proposal of Short
Proxy Signature Using Pairing. In: International
Conference on Information Technology (ITCC 2005). USA:
IEEE press, 2005: 631–635.
[7] Huang X.Y., Mu Y., Susilo W., et al. A Short Proxy
Signature Scheme: Efficient Authentication in the
Ubiquitous World. In: EUCWorkshops 2005. Berlin:
Springer-Verlag, 2005: 480–489.
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