14-02-2015, 07:16 AM
I need source code for digital signature with rsa encryption algorithm.
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source code for digital signature with rsa encryption algorithm
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I need source code for digital signature with rsa encryption algorithm.
07-04-2017, 12:45 PM
Digital signatures are the public key authentication keys for messages. In the physical world, it is common to use handwritten signatures in handwritten or typed messages. They are used to force the signer of the message. Similarly, a digital signature is a technique that links a person / entity to digital data. This binding can be independently verified by the recipient, as well as any third party. The digital signature is a cryptographic value that is calculated from the data and a secret key known only by the signer. In the real world, the recipient of the message needs the assurance that the message belongs to the sender and should not be able to repudiate the origin of that message. This requirement is very crucial in enterprise applications, since the probability of a dispute over the exchanged data is very high.
Signing a document with pen and ink (the obvious equivalent of a digital signature) is quite different from opening a padlock with a key (perhaps the least obvious equivalent of decryption). However, both involve the use of a secret: how to write your own distinctive signature, and the shape of a distinctive key.
There are algorithms for digital signatures and algorithms for encryption schemes. Sometimes it turns out that the key idea underlying an algorithm can be used for both purposes. For example, the key idea behind the El Gamal encryption algorithm can also be used to construct a digital signature algorithm. The same is true for the well-known RSA algorithm.
Unfortunately, there is a tendency to oversimplify by stating that digital signature algorithms are the same as the corresponding encryption scheme algorithms. They are not. However, you will sometimes find statements that (for example) the RSA signature is the same as the RSA decryption. That type of claim is partly true, but also partly false.
RSA Digital Signatures
The notion of digital signatures goes back to the beginning of public key cryptography. Whitfield Diffie and Martin Hellman introduced the idea that someone could form a digital signature using public key cryptography that anyone else could verify, but that no one else could generate.
While Diffie and Hellman provided a general model for digital signatures of any kind, the method developed by Rivest, Shamir and Adleman in 1977, known as "RSA", has become the most tested and most popular and achieved the widest Adoption by standards AND in practice. Other methods, discrete logarithm cryptography (including the Digital Signature Algorithm and the Diffie-Hellman key agreement method) and elliptic curve cryptography (see "Elliptic Curves and Cryptography" by Aleksandar Jurisic and Alfred J. Menezes, DDJ, April 1997). It has also been incorporated into several standards, but none of them have been so widely adopted in practice as RSA.
The signature can then be verified by applying the corresponding public key to the message and signature through the verification process, providing a valid or invalid result. These two operations - sign and verify - comprise the RSA digital signature scheme.
Any signature generated by the first operation will always verify correctly with the second operation if the corresponding public key is used. If the signature was generated differently or if the message was altered after being signed, the chances that the second operation will verify correctly are extremely small; With typical parameters, the probability is approximately 1 in 2160 or essentially zero. Although there are better ways of forging a signature than simply guessing, using a sufficiently large key ensures security by making it computationally impractical to do so. For example, it has been estimated that taking thousands or even millions of years to break a particular 1024-bit key (finding the private key, given the public key), depending on the amount of computing power applied.
Signing a document with pen and ink (the obvious equivalent of a digital signature) is quite different from opening a padlock with a key (perhaps the least obvious equivalent of decryption). However, both involve the use of a secret: how to write your own distinctive signature, and the shape of a distinctive key.
There are algorithms for digital signatures and algorithms for encryption schemes. Sometimes it turns out that the key idea underlying an algorithm can be used for both purposes. For example, the key idea behind the El Gamal encryption algorithm can also be used to construct a digital signature algorithm. The same is true for the well-known RSA algorithm.
Unfortunately, there is a tendency to oversimplify by stating that digital signature algorithms are the same as the corresponding encryption scheme algorithms. They are not. However, you will sometimes find statements that (for example) the RSA signature is the same as the RSA decryption. That type of claim is partly true, but also partly false.
RSA Digital Signatures
The notion of digital signatures goes back to the beginning of public key cryptography. Whitfield Diffie and Martin Hellman introduced the idea that someone could form a digital signature using public key cryptography that anyone else could verify, but that no one else could generate.
While Diffie and Hellman provided a general model for digital signatures of any kind, the method developed by Rivest, Shamir and Adleman in 1977, known as "RSA", has become the most tested and most popular and achieved the widest Adoption by standards AND in practice. Other methods, discrete logarithm cryptography (including the Digital Signature Algorithm and the Diffie-Hellman key agreement method) and elliptic curve cryptography (see "Elliptic Curves and Cryptography" by Aleksandar Jurisic and Alfred J. Menezes, DDJ, April 1997). It has also been incorporated into several standards, but none of them have been so widely adopted in practice as RSA.
The signature can then be verified by applying the corresponding public key to the message and signature through the verification process, providing a valid or invalid result. These two operations - sign and verify - comprise the RSA digital signature scheme.
Any signature generated by the first operation will always verify correctly with the second operation if the corresponding public key is used. If the signature was generated differently or if the message was altered after being signed, the chances that the second operation will verify correctly are extremely small; With typical parameters, the probability is approximately 1 in 2160 or essentially zero. Although there are better ways of forging a signature than simply guessing, using a sufficiently large key ensures security by making it computationally impractical to do so. For example, it has been estimated that taking thousands or even millions of years to break a particular 1024-bit key (finding the private key, given the public key), depending on the amount of computing power applied.
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