Difference between revisions of "Digital Signature"
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| + | [[Category:Knowledge Base]] |
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| − | A digital signature is the result of a mathematical computation. It is similar to a hash value such as MD5, but there is one important difference: |
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| + | A digital signature is the result of a mathematical computation. It is similar to a hash value such as [[MD5]], but there is one important difference: |
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a digital signature relies on a private/public key scheme. Thus one key (typically the private key) is used to generate the signature, and |
a digital signature relies on a private/public key scheme. Thus one key (typically the private key) is used to generate the signature, and |
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the other one is used to verify it, unlike a hash which is a simple mathematical function result, where the same function is used for both generation |
the other one is used to verify it, unlike a hash which is a simple mathematical function result, where the same function is used for both generation |
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and verification. |
and verification. |
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| − | This is a very important difference. With a digital signature verification scheme, both the algorithm and public key can be open |
+ | This is a very important difference. With a digital signature verification scheme, both the algorithm and public key can be known and open but this still does not allow a potential attacker to create a signature for a modified document. |
| − | This still does not allow a potential attacker to create a signature for a modified document. |
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| − | Applications |
+ | ==Applications== |
| − | There are various applications for digital signatures in Embedded Systems and other places. One simple example is Signature of a document |
+ | There are various applications for digital signatures in Embedded Systems and other places. One simple example is the Signature of a document. |
| − | Alice can make her public key known to the world, and anybody can now verify that a document |
+ | Alice can make her public key known to the world, and anybody can now verify that a document claiming to be signed by Alice actually was. |
| − | The only thing they have to |
+ | The only thing they have to ensure is that they have the proper public key (used for verification). |
| − | SEGGER supplies a free tool based on emSecure for exactly this purpose: [ |
+ | SEGGER supplies a free tool based on emSecure for exactly this purpose: [https://www.segger.com/products/security-iot/emsecure/tools/signverify/ Sign&Verify]. |
| + | ==In Embedded Systems== |
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In Embedded Systems, Digital Signatures can be used for various purposes, such as |
In Embedded Systems, Digital Signatures can be used for various purposes, such as |
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*Firmware updates - Authenticate the source of the firmware update |
*Firmware updates - Authenticate the source of the firmware update |
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| − | *Copy (clone) protection - Using the unique ID of a chip in the system, every device |
+ | *Copy (clone) protection - Using the unique ID of a chip in the system, every device will store a signature based on this unique ID. When copied (cloned), if the signature does not match, the firmware will refuse to function. |
| − | Algorithms used |
+ | ==Algorithms used== |
| − | *RSA |
+ | *[[RSA]] |
*Elliptic curves |
*Elliptic curves |
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| − | Software libraries |
+ | ==Software libraries== |
| − | One software library that allows generation of keys as well as signature and verification of signatures in any system including Embedded Systems is SEGGER's |
+ | One software library that allows generation of keys as well as signature and verification of signatures in any system including Embedded Systems is SEGGER's [https://www.segger.com/products/security-iot/emsecure/ emSecure] |
Latest revision as of 17:26, 28 May 2019
A digital signature is the result of a mathematical computation. It is similar to a hash value such as MD5, but there is one important difference: a digital signature relies on a private/public key scheme. Thus one key (typically the private key) is used to generate the signature, and the other one is used to verify it, unlike a hash which is a simple mathematical function result, where the same function is used for both generation and verification.
This is a very important difference. With a digital signature verification scheme, both the algorithm and public key can be known and open but this still does not allow a potential attacker to create a signature for a modified document.
Applications
There are various applications for digital signatures in Embedded Systems and other places. One simple example is the Signature of a document. Alice can make her public key known to the world, and anybody can now verify that a document claiming to be signed by Alice actually was. The only thing they have to ensure is that they have the proper public key (used for verification). SEGGER supplies a free tool based on emSecure for exactly this purpose: Sign&Verify.
In Embedded Systems
In Embedded Systems, Digital Signatures can be used for various purposes, such as
- Firmware updates - Authenticate the source of the firmware update
- Copy (clone) protection - Using the unique ID of a chip in the system, every device will store a signature based on this unique ID. When copied (cloned), if the signature does not match, the firmware will refuse to function.
Algorithms used
- RSA
- Elliptic curves
Software libraries
One software library that allows generation of keys as well as signature and verification of signatures in any system including Embedded Systems is SEGGER's emSecure
