The Bank of Canada is planning another redesign of Canadian banknotes as part of a strategy to stay ahead of counterfeiters, the central bank's deputy governor says.

"As I speak, my colleagues at the bank are hard at work designing the next generation of banknotes, planned for introduction beginning in 2011," David Longworth said during a Chamber of Commerce speech in Kitchener-Waterloo, Ont., on Tuesday.

The most common counterfeited bills are $10 and $20 notes, RCMP figures show.

Bank of Canada spokesperson Cristian Vezeau told CBC News Online that the next redesign will offer a "significant increase in security."

Longworth outlined several anti-counterfeiting measures.

"By 2009, we aim to reduce the level of counterfeiting to fewer than 100 counterfeits detected annually per million notes in circulation," he said. That's down from 225 per million in 2006, 326 per million in 2005 and 470 per million in 2004.

An internal bank report made public last year revealed that the bank felt counterfeiting had reached "dangerous levels," according to documents obtained by the Canadian Press.

The central bank considers anything over 120 counterfeits per million to be a problem.

About 402,000 counterfeit notes were passed in 2005, and 553,000 in 2004.

The main objective of the Bank of Canada's currency work is to give Canadians "paper money that can be trusted," Longworth said.

He said Canadians have a high level of confidence in their money. "They use banknotes for day-to-day transactions without worrying unduly about counterfeiting," he said.

"Can we do better?" Longworth asked his audience, just before answering his own question. "We think we can."

The steady reduction in the rate of counterfeit notes is due, in part, to a wholesale redesign of all Canadian banknotes in the past few years to incorporate added security features.