MPs on the Scottish Affairs Committee claimed the Scottish government had failed to cost its plans properly for both public and private pensions.
But the SNP challenged the pro-Union parties to publish their own plans for the state pension.
The party also accused the main Westminster parties of carrying out a “pensions con” on people in Scotland.
The Scottish Affairs Committee report said the Scottish government’s stated plans to consider delaying the increase in the pension age to 67 and to pay a proposed higher starting rate than the rest of the UK were “almost entirely uncosted”.
It called on the Holyrood administration to give a clear proposal for a future pension age and the full price of its plans before the referendum, so that current and future pensioners can judge how much more expensive they would be.
The committee also said it had heard evidence that the proposed Scottish version of the UK government’s National Employment Savings Trust (Nest) would fail to match the value for money of the current UK system and could take a long time to set up.
It said that many public pension schemes were not currently funded up to sufficient levels to cover all their commitments so the UK government would step in with additional funding.
But the committee’s report said the Scottish government had failed to make clear how much it would cost Scotland to bear these costs after independence.
On working age benefits, the report said the Scottish government’s plans had failed to acknowledge the costs and complexities of disentangling Scottish claimants from the UK welfare system.
It also said that the Scottish government’s plans to run two parallel systems in a transition period to independence were unfeasible.
And it raised what it said were “serious doubts” on whether an independence Scotland could set up a new benefits system by 2018, saying the time frame was “unrealistic”.
The committee, which is being boycotted by the SNP, is comprised of pro-UK politicians.
Its chairman, Labour MP Ian Davidson, claimed the Scottish government’s plans for pensions in an independent Scotland amounted to the “biggest mis-selling scandal in history”.
He said: “The only thing definite about the Scottish government’s welfare policies is uncertainty.
“They cannot say what their pensions bill would be. They have no credible plans to cope with the rising costs of Scotland’s ageing population. They don’t know what their own promises would cost.
“Pensioners – current and future – deserve certainty. Instead the Scottish government offer no detail, no costings, no believable plan and what they are offering amounts to the biggest mis-selling scandal in history.”
The Scottish government has set out proposals for what it said would be an “affordable, fair and efficient” pensions system in its White Paper on independence.
It has said that social protection spending, which includes pensions and welfare, has been more affordable in Scotland than in the rest of the UK for the past five years.
And it has said that its proposals would provide a more generous pension in Scotland after independence, with pensioners being offered a guaranteed pension of £160 a week from 2016-17, a triple lock and the continuation of savings credit.
The SNP’s welfare spokeswoman, Eilidh Whiteford – who withdrew from the Scottish Affairs Committee over claims she was threatened by Mr Davidson – accused the pro-UK parties of “playing games” around pension policy.
She added: “Pensioners have worked all their lives and made their contribution and we should ensure they receive decent pensions.
“Scotland has paid more in taxes in each and every one of the last 30 years than the rest of the UK, much of it through the efforts of those who are now pensioners and with independence we will ensure pensioners get the support they are rightly entitled to.
“The UK and Scottish governments have guaranteed that pensions will continue to be paid whatever the result of the referendum and the Scottish government has confirmed pensions will be set at a minimum of £160 a week in 2016-17.
“The UK government and the Labour party have failed to tell pensioners what they intend to pay or confirm they will ensure pensions keep pace with the cost of living. Instead of trying to pull the wool over people’s eyes Labour and the UK Government should set out their position on the future of the state pension.”