This site is the archived OWASP Foundation Wiki and is no longer accepting Account Requests.
To view the new OWASP Foundation website, please visit https://owasp.org
Difference between revisions of "ProblemsCBCModeForPANs"
(New page: 1. Abstract * Permanant Account Number (PAN) encryption in an ecommerce merchant databases presents unique application issues. * Block encryption primitives using Ciphe...) |
|||
| (7 intermediate revisions by the same user not shown) | |||
| Line 1: | Line 1: | ||
| + | Link To Document - | ||
| + | [https://www.owasp.org/index.php/Image:PanEncryption.pdf Problems With Using CBC Mode For PAN Encryption] | ||
| − | + | '''Author Ashok Misra''' | |
| − | + | '' | |
| − | + | Abstract'' | |
| − | + | Permanant Account Number (PAN) encryption in an ecommerce merchant | |
| − | + | databases presents unique application issues. | |
| − | |||
| − | + | Block encryption primitives using Cipher Block Chaining (CBC) mode | |
| − | + | preclude the possibility of supporting an efficient lookup | |
| + | functionality. | ||
| − | + | Since CBC encryption mode is not idempotent, one way hashes for | |
| − | + | PANs are needed in order to support lookup. | |
| − | |||
| − | + | The payment community does not view a one way hash of a PAN as a | |
| − | + | security violation. Ironicaly, its use is recommended by PCI DSS best | |
| − | + | practices. | |
| − | + | On the other hand, security experts categorically proscribe the use of | |
| − | + | an idempotent block cipher implementation such as Electronic Code Book | |
| + | (ECB). | ||
| − | + | Storage of SHA1 hashes for payment information follows best practise, | |
| − | + | PCI guidelines and buzzword compliance. | |
| − | + | ||
| + | This paper presents a minority opinion and argues that security is | ||
| + | weakened dramatically by employing one way cryptographic primitives | ||
| + | for PANs in order to support lookup. | ||
Latest revision as of 18:00, 14 July 2008
Link To Document - Problems With Using CBC Mode For PAN Encryption
Author Ashok Misra
Abstract
Permanant Account Number (PAN) encryption in an ecommerce merchant databases presents unique application issues.
Block encryption primitives using Cipher Block Chaining (CBC) mode preclude the possibility of supporting an efficient lookup functionality.
Since CBC encryption mode is not idempotent, one way hashes for PANs are needed in order to support lookup.
The payment community does not view a one way hash of a PAN as a security violation. Ironicaly, its use is recommended by PCI DSS best practices.
On the other hand, security experts categorically proscribe the use of an idempotent block cipher implementation such as Electronic Code Book (ECB).
Storage of SHA1 hashes for payment information follows best practise, PCI guidelines and buzzword compliance.
This paper presents a minority opinion and argues that security is weakened dramatically by employing one way cryptographic primitives for PANs in order to support lookup.
