Create a new IAM role in Account A that can publish to any SQS queue. Share the role ARN with Account B.

Add SNS topic ARNs to SQS queue policies in Account B. Configure SNS topics to publish to any queue. Encrypt the queue with an AWS KMS key.

Modify the SQS queue policies in Account B to allow only specific SNS topic ARNs from Account A to publish messages. Ensure the SNS topics have publish permissions for the specific queue ARN.

Create a shared IAM role across both accounts with permission to publish to all SQS queues. Enable cross-account access.