Comparing checksums is the most effective method listed for ensuring data integrity during migration. A checksum or hash function generates a unique digital fingerprint for a dataset. By calculating the checksum of the data on the source database before migration and comparing it with the checksum of the data on the destination hardware after migration, the organization can verify that the data has not been altered, corrupted, or incompletely transferred. A match provides a high degree of assurance that the data's integrity has been preserved.

A. Reconciling sample data is not comprehensive, as it only verifies a small subset of the data, leaving the integrity of the majority of the data unconfirmed.
B. Obfuscating confidential data is a security control for confidentiality, not integrity. It intentionally alters data to protect sensitive information, which is counterproductive to verifying an exact copy.
C. Encrypting the data is a control for confidentiality, protecting it from unauthorized access during transit or at rest. It does not, by itself, verify that the data is complete and unaltered.

1. ISACA

CISA Review Manual

27th Edition. Domain 3: Information Systems Acquisition

Development

and Implementation

Section 3.5.4

"Data Conversion

" emphasizes the need for controls to ensure data integrity during the conversion process. It states

"The IS auditor should verify that... controls are in place to ensure the integrity of the data." Hashing (checksums) is a primary technical control for this purpose.

2. ISACA

"Data Migration: An Auditing Perspective

" White Paper

2011. Page 6 discusses post-migration testing

stating

"The audit team should ensure that the project team has performed sufficient testing... This can be done by comparing record counts

control totals or hash totals between the source and target systems." This directly supports using checksums (hash totals) for integrity verification.

3. Purdue University

"Introduction to Cryptography" (CS 490-CR1)

Lecture Notes. Course materials on cryptographic primitives consistently define one of the primary applications of hash functions as integrity checking. The notes explain that if H(M1) = H(M2)

it is computationally certain that the messages M1 and M2 are identical

which is the principle behind using checksums for migration verification.